# Nitrogen narcosis ## Microsim ### Live player <div class="microsim-player"> <iframe src="https://editor.p5js.org/sciencenibber/full/3OQ1crZ1T" width="100%" height="620" frameborder="0" sandbox="allow-scripts allow-same-origin"></iframe> </div> <div class="microsim-fallback"> <img src="Microsims/thumbs/Nitrogen_narcosis.png" alt="Nitrogen_narcosis microsim poster" style="width:100%;border:1px solid #4445;border-radius:6px;"> <p><em>Live microsim (desktop) · <a href="https://editor.p5js.org/sciencenibber/sketches/3OQ1crZ1T">open sketch in the p5.js editor</a></em></p> </div> **Editor URL:** https://editor.p5js.org/sciencenibber/sketches/3OQ1crZ1T **Description (100 words):** A vertical seawater column on the left lets the reader drag a scuba diver from the surface down to eighty metres. Bubbles rise from the diver's regulator in colours weighted by the current breathing mix. On the right, a stylised brain fills with dissolved-gas particles whose count and jitter scale with the live narcotic dose; a dashed marker on the column flags the thirty-metre air-narcosis threshold. Gauges show ambient pressure, nitrogen partial pressure, equivalent narcotic depth, and martini-units, with a symptom label running from "alert" to "stupor risk". Three buttons switch between Air, Heliox, and Trimix, and a Meyer-Overton bar compares helium, nitrogen, argon, and xenon. ```js // ===================================================================== // Nitrogen_narcosis.js -- Wikitube microsim // Article: Nitrogen narcosis en.wikitube.io/wiki/Nitrogen_narcosis // Room: Helium Pattern: E (particle systems, kinetics) // --------------------------------------------------------------------- // Idea: a draggable scuba diver descends through a vertical seawater // column from 0 m to 80 m. Bubbles of the chosen breathing gas rise // past the diver; inside a stylised brain on the right, dissolved // inert-gas particles accumulate and jitter at a rate proportional // to the narcotic dose. Three gas-mix buttons swap the gas (Air / // Heliox 80-20 / Trimix 18-45-37). The reader watches Martini's law // in action: on air, narcosis crosses threshold at 30 m and adds // one martini-equivalent per 15 m beyond. On heliox, the diver // stays clear even at 80 m -- because helium is essentially non- // narcotic. On trimix the threshold shifts deep. // // Equations (shown live in the HUD): // P_amb = 1 + d / 10 [bar] // p_N2 = F_N2 * P_amb [bar] // END = ( (F_N2 / 0.79) * P_amb - 1 ) * 10 [m, equivalent // narcotic depth] // Martini = max(0, (END - 30) / 15) [martini units] // // Meyer-Overton correlation, oil/gas partition coefficients // (normalised to N2 = 1; the central insight of the article): // N2 = 1.00 He = 0.045 Ar = 2.3 Xe = 25.6 // The mass-action picture: narcotic potency tracks the lipid // solubility of the inert gas. Helium's coefficient is ~22x lower // than nitrogen's, which is why heliox eliminates narcosis at // depths where air would put a diver into stupor. // // Visual layout (720 x 520 canvas): // * top-left: HUD title + Wikitube subtitle // * top-right: gas-mix buttons (Air / Heliox / Trimix) // * left half: vertical water column with depth ticks (0..80 m) // * diver: silhouette at current depth, draggable // * bubbles: rising particles colored by breathing-gas mix // * right top: stylised brain outline filled with dissolved- // gas particles; count and jitter encode dose // * right mid: gauges (P_amb, p_N2, END, Martini count, label) // * right bot: Meyer-Overton bar comparing N2 / He / Ar / Xe // * bottom-rt: canonical equation pN2 = F_N2 * P_amb // // Pattern E (P5_JS_EDITOR section 4 line 157, "phase transitions // and equilibria"): a particle field re-organises from alert (few // jittery dots) to stupor (dense, frantic) as the narcotic dose // climbs. Same Pattern E shape used for thermal-equilibrium and // Ising-model articles, here reskinned to a clinical dose-response. // // Conventions (Wikitube Betterfire Standard v0): // * single ARTICLE constant at the top, single quotes // * p5.disableFriendlyErrors = true (silences FES in editor) // * non-ASCII characters (Greek mu, dots, lambdas) live in // COMMENTS ONLY -- every text() string literal is pure ASCII // * Energy-room palette (P5_JS_EDITOR section 4 line 165): // BG=18, FG=240, HOT/COLD/STRUCT/TRAJ // ===================================================================== const ARTICLE = 'Nitrogen_narcosis'; const TITLE = ARTICLE.replace(/_/g, ' '); p5.disableFriendlyErrors = true; // ----- Energy room palette (P5_JS_EDITOR section 4) ------------------ const BG = 18; const FG = 240; const DIM = [240, 240, 240, 150]; const HOT = [220, 110, 60]; // warm: O2 / narcosis label / hazard const COLD = [60, 130, 220]; // cool: N2 (nitrogen) const COLDER = [40, 80, 180]; // deeper water column tint const STRUCT = [120, 130, 150]; // structural grey: axes, brain outline const TRAJ = [240, 220, 80]; // accent: diver, martini gauge fill const ACCENT = [180, 230, 240]; // cyan-white: helium const SCRATCH = [120, 120, 120, 90]; // ----- Gas mix presets (mole fractions sum to 1) --------------------- const MIXES = [ { name: 'Air', FN2: 0.79, FO2: 0.21, FHe: 0.00 }, { name: 'Heliox 80/20', FN2: 0.00, FO2: 0.20, FHe: 0.80 }, { name: 'Trimix 18/45', FN2: 0.37, FO2: 0.18, FHe: 0.45 } ]; let mixIdx = 0; // currently selected mix index into MIXES[] // ----- Meyer-Overton oil/gas partition coefficients ------------------ // Normalised so nitrogen = 1.00. Values from standard hyperbaric- // medicine tables (e.g. Bennett & Elliott, "The Physiology and // Medicine of Diving"). The Meyer-Overton correlation says these // coefficients predict narcotic potency to within a factor of two. const MO = { He: 0.045, N2: 1.00, Ar: 2.30, Xe: 25.6 }; // ----- Water-column geometry (left half of canvas) ------------------- let colX, colY, colW, colH; const D_MIN = 0; // m const D_MAX = 80; // m // ----- Brain geometry (right half, top) ------------------------------ let brainCX, brainCY, brainRX, brainRY; // ----- Diver state (depth in metres) --------------------------------- let depth = 18; // start mid-recreational, just shy of threshold let dragging = false; // ----- Particle systems ---------------------------------------------- // Bubbles rising past the diver. Each spawns at diver mouth, rises to // surface, despawns. The colour encodes which inert species dominates // the current breathing mix. const bubbles = []; const BUBBLE_MAX = 80; // Dissolved-gas particles inside the brain. Active count and jitter // amplitude both scale with narcotic dose (martini-equivalents). The // total is a fixed pool, of which only the first nActive are drawn. const POOL = 140; const dots = new Array(POOL).fill(null).map(makeDot); function makeDot() { return { x: 0, y: 0, ax: 0, ay: 0 }; // ax,ay = anchor inside brain } // ----- Gas-mix buttons (created in setup, positioned top-right) ------ let btnAir, btnHeliox, btnTrimix; function setup() { createCanvas(720, 520); pixelDensity(2); textFont('system-ui'); // Water column: left half of canvas. colX = 40; colY = 70; colW = 200; colH = height - 100; // Brain: upper-right quadrant. Generous radii to leave gauge room. brainCX = 520; brainCY = 170; brainRX = 130; brainRY = 80; // Seed dot anchors uniformly inside the brain ellipse. for (const d of dots) { let placed = false; let tries = 0; while (!placed && tries < 50) { const u = random(-1, 1); const v = random(-1, 1); if (u * u + v * v <= 1) { d.ax = brainCX + u * (brainRX - 8); d.ay = brainCY + v * (brainRY - 8); d.x = d.ax; d.y = d.ay; placed = true; } tries++; } } // Gas-mix buttons (top-right of canvas). Per Betterfire Standard // every control gets an explicit .position() and .size(). btnAir = createButton('Air').position( width - 250, 14).size(70, 24); btnHeliox = createButton('Heliox').position(width - 175, 14).size(70, 24); btnTrimix = createButton('Trimix').position(width - 100, 14).size(86, 24); btnAir.mousePressed( () => mixIdx = 0); btnHeliox.mousePressed(() => mixIdx = 1); btnTrimix.mousePressed(() => mixIdx = 2); } function draw() { background(BG); const mix = MIXES[mixIdx]; const P_amb = 1 + depth / 10; const pN2 = mix.FN2 * P_amb; const END = Math.max(0, ((mix.FN2 / 0.79) * P_amb - 1) * 10); const martini = Math.max(0, (END - 30) / 15); // Draw order: water column (cheap raster), depth ticks, diver + // bubbles, brain + dissolved-gas particles, gauges, HUD on top. drawWaterColumn(); spawnBubble(mix); updateAndDrawBubbles(); drawDiver(); drawBrain(); updateAndDrawDots(martini, mix); drawGauges(P_amb, pN2, END, martini, mix); drawMeyerOverton(); drawHUD(); } // ===================================================================== // Coordinate transforms: depth (m) <-> canvas pixel y // ===================================================================== function depthToY(d) { return map(d, D_MIN, D_MAX, colY, colY + colH); } function yToDepth(y) { return constrain(map(y, colY, colY + colH, D_MIN, D_MAX), D_MIN, D_MAX); } // ===================================================================== // Water column: vertical gradient + depth ticks // ===================================================================== function drawWaterColumn() { // Vertical gradient: surface light cyan -> deep dark navy. // Implemented as a row of horizontal lines (cheap and editor-safe). noFill(); for (let y = colY; y < colY + colH; y++) { const t = (y - colY) / colH; const r = lerp(120, 8, t); const g = lerp(180, 22, t); const b = lerp(230, 60, t); stroke(r, g, b); line(colX, y, colX + colW, y); } // Surface line (white waterline). stroke(FG, 220); strokeWeight(1); line(colX, colY, colX + colW, colY); // Depth ticks every 10 m, labels on the right edge of the column. noStroke(); fill(...DIM); textSize(10); textAlign(LEFT, CENTER); for (let d = 0; d <= D_MAX; d += 10) { const y = depthToY(d); stroke(SCRATCH); line(colX + colW, y, colX + colW + 6, y); noStroke(); fill(...DIM); text(d + ' m', colX + colW + 10, y); } // Narcosis-threshold marker at 30 m (Martini's law starting depth). stroke(HOT[0], HOT[1], HOT[2], 180); strokeWeight(1); drawingContext.setLineDash([4, 4]); line(colX, depthToY(30), colX + colW, depthToY(30)); drawingContext.setLineDash([]); noStroke(); fill(HOT[0], HOT[1], HOT[2], 220); textSize(10); textAlign(RIGHT, BOTTOM); text('air narcosis threshold (30 m)', colX + colW - 4, depthToY(30) - 3); } // ===================================================================== // Diver: simple silhouette, draggable up/down // ===================================================================== function drawDiver() { const dx = colX + colW / 2; const dy = depthToY(depth); push(); translate(dx, dy); // Tank on back (cylinder behind shoulders). fill(...STRUCT); noStroke(); rectMode(CENTER); rect(8, -2, 8, 24, 2); // Body (torso + legs as a tapered shape). fill(...TRAJ); beginShape(); vertex(-6, -10); vertex( 6, -10); vertex( 8, 10); vertex( 4, 22); vertex(-4, 22); vertex(-8, 10); endShape(CLOSE); // Head + mask. fill(255, 220, 180); circle(0, -16, 14); noFill(); stroke(40); strokeWeight(2); arc(0, -16, 12, 8, PI, TWO_PI); // mask top edge noStroke(); // Air hose / regulator hint. stroke(...STRUCT); strokeWeight(1.5); noFill(); line(0, -10, 14, -2); noStroke(); // Flipper. fill(40); triangle(-4, 22, 4, 22, 0, 30); rectMode(CORNER); pop(); // Drag hint halo when hovering. if (mouseInDiver()) { noFill(); stroke(TRAJ[0], TRAJ[1], TRAJ[2], 160); strokeWeight(1); circle(dx, dy, 56); } } function mouseInDiver() { const dx = colX + colW / 2; const dy = depthToY(depth); return dist(mouseX, mouseY, dx, dy) < 28; } // ===================================================================== // Bubble particle system: rising bubbles from the diver // ===================================================================== function spawnBubble(mix) { if (bubbles.length >= BUBBLE_MAX) return; if (random() > 0.45) return; // ~45% spawn-rate per frame // Pick a component of the current mix weighted by mole fraction. // Bubble colour encodes which gas the reader is "seeing". const r = random(); let species; if (r < mix.FN2) species = 'N2'; else if (r < mix.FN2 + mix.FHe) species = 'He'; else species = 'O2'; let col; if (species === 'N2') col = [COLD[0], COLD[1], COLD[2]]; else if (species === 'He') col = [ACCENT[0], ACCENT[1], ACCENT[2]]; else col = [HOT[0], HOT[1], HOT[2]]; const dx = colX + colW / 2; const dy = depthToY(depth); bubbles.push({ x: dx + random(-4, 14), // slight rightward drift (regulator side) y: dy - 12, // emit just above the mask vy: random(-1.8, -0.7), r: random(2, 4.5), col: col, life: 1.0 }); } function updateAndDrawBubbles() { for (let i = bubbles.length - 1; i >= 0; i--) { const b = bubbles[i]; b.y += b.vy; b.x += sin(frameCount * 0.05 + i) * 0.3; // tiny lateral wobble b.vy *= 0.997; // negligible drag // Despawn at surface. if (b.y < colY - 4) { bubbles.splice(i, 1); continue; } noStroke(); fill(b.col[0], b.col[1], b.col[2], 170); circle(b.x, b.y, b.r * 2); fill(255, 200); circle(b.x - b.r * 0.4, b.y - b.r * 0.4, b.r * 0.7); // specular hint } } // ===================================================================== // Brain + dissolved-gas particle field (Pattern E core) // ===================================================================== function drawBrain() { push(); // Brain outline (stylised ellipse with a sagittal fissure line). noFill(); stroke(...STRUCT); strokeWeight(2); ellipse(brainCX, brainCY, brainRX * 2, brainRY * 2); // Sagittal cleft hint stroke(STRUCT[0], STRUCT[1], STRUCT[2], 120); strokeWeight(1); line(brainCX, brainCY - brainRY + 6, brainCX, brainCY + brainRY - 6); // Brainstem nub at bottom (orienting cue). noStroke(); fill(STRUCT[0], STRUCT[1], STRUCT[2], 200); rect(brainCX - 8, brainCY + brainRY - 4, 16, 10, 4); // Label noStroke(); fill(...DIM); textSize(10); textAlign(CENTER, BOTTOM); text('CNS lipid bilayer (dissolved inert gas)', brainCX, brainCY - brainRY - 6); pop(); } function updateAndDrawDots(martini, mix) { // Active count: at zero dose, 12 baseline dots; ramps up to POOL // by ~4.5 martini units. Jitter amplitude tracks dose too. const nActive = Math.round(constrain(12 + martini * 28, 12, POOL)); const jitter = 0.3 + martini * 0.9; // Colour mixes the dominant inert species in the current breathing // gas. Heliox shows cyan/white dots (helium); air shows blue (N2); // trimix shows a blend weighted by mole fractions. const w = mix.FN2 + mix.FHe; const fN = w > 0 ? mix.FN2 / w : 0; const fH = w > 0 ? mix.FHe / w : 0; const r = fN * COLD[0] + fH * ACCENT[0]; const g = fN * COLD[1] + fH * ACCENT[1]; const b = fN * COLD[2] + fH * ACCENT[2]; // Symptom-tinted halo behind the dots when narcotic dose is high. if (martini > 0.5) { noStroke(); const haloA = constrain(martini * 28, 0, 110); fill(HOT[0], HOT[1], HOT[2], haloA); ellipse(brainCX, brainCY, brainRX * 2 - 8, brainRY * 2 - 8); } noStroke(); for (let i = 0; i < nActive; i++) { const d = dots[i]; // Random walk around the anchor with amplitude = jitter (px). d.x = d.ax + (d.x - d.ax) * 0.85 + random(-jitter, jitter); d.y = d.ay + (d.y - d.ay) * 0.85 + random(-jitter, jitter); fill(r, g, b, 220); circle(d.x, d.y, 4); } } // ===================================================================== // Gauges + symptom label // ===================================================================== function drawGauges(P_amb, pN2, END, martini, mix) { const gx = 380; const gy = 280; const gw = 300; push(); noStroke(); textAlign(LEFT, TOP); // Header fill(...DIM); textSize(11); text('mix: ' + mix.name + ' F_N2 = ' + nf(mix.FN2, 1, 2) + ' F_He = ' + nf(mix.FHe, 1, 2), gx, gy); // Numbers fill(FG); textSize(13); text('P_amb = ' + nf(P_amb, 1, 2) + ' bar', gx, gy + 22); text('p_N2 = ' + nf(pN2, 1, 2) + ' bar', gx, gy + 42); text('END = ' + nf(END, 1, 1) + ' m', gx + 150, gy + 22); text('depth = ' + nf(depth, 1, 1) + ' m', gx + 150, gy + 42); // Martini-units bar (0..5) textSize(12); fill(...DIM); text('narcotic dose (martini eq)', gx, gy + 66); fill(TRAJ[0], TRAJ[1], TRAJ[2], 60); rect(gx, gy + 82, gw, 12); const frac = constrain(martini / 5, 0, 1); fill(...TRAJ); rect(gx, gy + 82, gw * frac, 12); // 1, 2, 3, 4 tick marks on the bar stroke(...STRUCT); for (let i = 1; i <= 4; i++) { const tx = gx + (i / 5) * gw; line(tx, gy + 82, tx, gy + 94); } noStroke(); fill(...DIM); textSize(10); text(nf(martini, 1, 2) + ' martini', gx + gw - 70, gy + 100); // Symptom label (the human-readable summary) textSize(13); let label, labelCol; if (martini < 0.5) { label = 'alert'; labelCol = ACCENT; } else if (martini < 1.5) { label = 'mild euphoria'; labelCol = TRAJ; } else if (martini < 2.5) { label = 'narrowed focus, slowed reflexes'; labelCol = TRAJ; } else if (martini < 3.5) { label = 'impaired judgment, incoordination'; labelCol = HOT; } else { label = 'stupor risk - ABORT depth'; labelCol = HOT; } fill(...labelCol); text('symptom: ' + label, gx, gy + 118); pop(); } // ===================================================================== // Meyer-Overton comparison bar (right-bottom) // ===================================================================== function drawMeyerOverton() { const bx = 380; const by = 430; const bw = 300; const bh = 10; const max = 26; // log-ish: Xe ~= 25.6 sets the scale push(); noStroke(); fill(...DIM); textSize(10); textAlign(LEFT, TOP); text('Meyer-Overton oil/gas partition (relative narcotic potency)', bx, by - 16); // Four bars stacked, labelled inline. const labels = ['He', 'N2', 'Ar', 'Xe']; const cols = [ACCENT, COLD, [200, 160, 80], HOT]; const vals = [MO.He, MO.N2, MO.Ar, MO.Xe]; for (let i = 0; i < 4; i++) { const y = by + i * (bh + 4); fill(cols[i][0], cols[i][1], cols[i][2], 60); rect(bx + 24, y, bw - 60, bh); const f = Math.min(1, vals[i] / max); fill(...cols[i]); rect(bx + 24, y, (bw - 60) * f, bh); fill(...DIM); textAlign(LEFT, CENTER); text(labels[i], bx, y + bh / 2); textAlign(RIGHT, CENTER); text(nf(vals[i], 1, 2), bx + bw - 4, y + bh / 2); } pop(); } // ===================================================================== // HUD: title, subtitle, hints, canonical equation // ===================================================================== function drawHUD() { // Top-left: title + Wikitube URL (Betterfire Standard rule 2) noStroke(); fill(FG); textAlign(LEFT, TOP); textSize(20); text(TITLE, 14, 12); fill(...DIM); textSize(12); text('Wikitube microsim . en.wikitube.io/wiki/Nitrogen_narcosis', 14, 36); // Top-right (under the buttons): brief control hint textAlign(RIGHT, TOP); textSize(10); text('drag the diver up/down . arrow keys nudge', width - 14, 44); // Bottom-right: canonical equation (Betterfire Standard rule 4) textAlign(RIGHT, BOTTOM); fill(FG); textSize(12); text('p_N2 = F_N2 * P_amb END = (F_N2/0.79 * P_amb - 1) * 10', width - 14, height - 6); } // ===================================================================== // Input handling // ===================================================================== function mousePressed() { // Begin dragging if click lands on/near diver, OR if click is // anywhere inside the water column (jump-to-depth + drag). if (mouseInDiver()) { dragging = true; return; } if (mouseX >= colX && mouseX <= colX + colW && mouseY >= colY && mouseY <= colY + colH) { depth = yToDepth(mouseY); dragging = true; } } function mouseDragged() { if (dragging) { depth = yToDepth(mouseY); } } function mouseReleased() { dragging = false; } function keyPressed() { // Arrow keys nudge depth in 1 m increments for fine control. if (keyCode === UP_ARROW) depth = Math.max(D_MIN, depth - 1); if (keyCode === DOWN_ARROW) depth = Math.min(D_MAX, depth + 1); // Number keys 1/2/3 select gas mix (keyboard alternative to buttons). if (key === '1') mixIdx = 0; if (key === '2') mixIdx = 1; if (key === '3') mixIdx = 2; } // ===================================================================== // End of Nitrogen_narcosis.js -- Wikitube microsim, Helium, Pattern E. // ===================================================================== ``` ## Links (Wikipedia order) <!-- injected from _registry/childlinks/Nitrogen_narcosis.json (2026-07-30T02:09:12Z) --> `14th_CMAS_Underwater_Photography_World_Championship` · `1973_Mount_Gambier_cave_diving_accident` · 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`Audrey_Mestre` · `Auguste_Denayrouze` · `Auguste_Piccard` · `Augustus_Siebe` · `Australian_Diver_Accreditation_Scheme` · `Australian_Underwater_Federation` · `Autonomous_diver` · `Avascular_necrosis` · `Avelo_diving_system` · `Bailout_bottle` · `Bar_(unit)` · `Barodontalgia` · `Barotrauma` · `Basic_Cave_Diving:_A_Blueprint_for_Survival` · `Bathyscaphe` · `Bathysphere` · `Ben_Cropp` · `Benzodiazepine` · `Bernard_Delemotte` · `Berry_L._Cannon` · `Beuchat` · `Bill_Nagle` · `Bill_Todd` · `Billy_Deans_(diver)` · `Bob_Behnken` · `Bob_Halstead` · `Bolt_snap` · `Booster_pump` · [[Breathing_gas]] · `Breathing_performance_of_regulators` · `Bret_Gilliam` · `Brian_Andrew_Hills` · `Brian_Kakuk` · `Brian_Skerry` · `British_Freediving_Association` · `British_Octopush_Association` · `British_Sub-Aqua_Club` · `British_Underwater_Sports_Association` · `Buddy_breathing` · `Buddy_check` · `Buddy_diving` · `Built-in_breathing_system` · `Buoyancy_compensator_(diving)` · `Byford_Dolphin` · `Bühlmann_decompression_algorithm` · `CMAS**_scuba_diver` · `CMAS*_scuba_diver` · `CMAS_Europe` · `COTSBot` · `CUMA` · `CURV` · `Canadian_Armed_Forces_Divers` · `Candice_Farmer` · `Canoe_and_kayak_diving` · `Carbon_dioxide` · `Carbon_dioxide_scrubber` · `Carbon_monoxide_poisoning` · `Carlos_Coste` · `Cascade_filling_system` · `Catherine_Coleman` · `Cathy_Church` · `Cave_Divers_Association_of_Australia` · `Cave_Diving_Group` · `Cave_diving` · `Cell_membrane` · `Charles_Anthony_Deane` · `Charles_Momsen` · `Charles_Spalding` · `Charles_T._Meide` · `Charles_Wesley_Shilling` · `Checklist` · `Chemical_bond` · `Children_in_scuba_diving` · `Chris_Hadfield` · `Christian_J._Lambertsen` · `Christopher_E._Gerty` · `Cis-Lunar` · `Civil_liability_in_recreational_diving` · `Claudia_Serpieri` · `Claustrophobia` · `Clayton_Anderson` · `Cleaning_and_disinfection_of_personal_diving_equipment` · `Clearance_Divers_Life_Support_Equipment` · `Clearance_Diving_Branch_(RAN)` · `Clearance_diver` · `Clive_Cussler` · `Cláudio_Coutinho` · `Code_of_practice` · `Cognition` · `Cold_shock_response` · `Comando_Raggruppamento_Subacquei_e_Incursori_Teseo_Tesei` · `Combat_sidestroke` · `Comhairle_Fo-Thuinn` · `Commercial_diver_registration_in_South_Africa` · `Commercial_offshore_diving` · `Compagnie_maritime_d'expertises` · `Competency-based_learning` · `Compression_arthralgia` · `Confédération_Mondiale_des_Activités_Subaquatiques` · `Consciousness` · `Constant_weight_bi-fins` · `Constant_weight_without_fins` · `Continental_Shelf_Station_Two` · `Contingency_plan` · `Convention_on_the_Protection_of_the_Underwater_Cultural_Heritage` · `Coral_Reef_Alliance` · `Cosmos_CE2F_series` · `Cotton_Coulson` · `Craig_B._Cooper` · `Craig_Challen` · `Craig_McKinley_(physician)` · `Cressi-Sub` · `Cristina_Zenato` · `DESCO` · `DIN_7876` · `DSRV-1_Mystic` · `DSRV-2_Avalon` · `DSV-5_Nemo` · `DSV_Alvin` · `DSV_Limiting_Factor` · `DSV_Sea_Cliff` · `DSV_Shinkai` · `DSV_Shinkai_2000` · `DSV_Shinkai_6500` · `DSV_Turtle` · `Dacor_(scuba_diving)` · `Dafydd_Williams` · `Danai_Varveri` · `Daniel_M._Tani` · `Dave_Mullins_(freediver)` · `Dave_Shaw` · `David_Attenborough` · `David_Bright_(diver)` · `David_Doubilet` · `David_Gibbins` · `David_Gruber` · `David_Saint-Jacques` · `Davis_Submerged_Escape_Apparatus` · `Death_of_Bradley_Westell` · `Death_of_Steve_Irwin` · `Deborah_Andollo` · `Decima_Flottiglia_MAS` · `Decompression_(diving)` · `Decompression_equipment` · `Decompression_illness` · `Decompression_practice` · `Decompression_sickness` · `Decompression_tables` · `Decompression_theory` · `Deep-sea_exploration` · `Deep-submergence_rescue_vehicle` · `Deep-submergence_vehicle` · `Deep_Drone` · `Deep_diving` · `Deepsea_Challenger` · `Defence_Diving_School` · `Defense_against_swimmer_incursions` · `Demand_valve_oxygen_therapy` · `Deon_Dreyer` · `Department_of_Employment_and_Labour` · `Depression_(mood)` · `Depth_gauge` · `Devrim_Cenk_Ulusoy` · `Dewey_Smith` · `Diamond_Reef_System` · `Diazepam` · `Dick_Rutkowski` · `Diethyl_ether` · `Diseases_Database` · `Distance_line` · `Dive_Xtras` · `Dive_boat` · `Dive_briefing` · `Dive_center` · `Dive_computer` · `Dive_leader` · `Dive_light` · `Dive_log` · `Dive_planning` · `Divemaster` · `Diver's_pump` · `Diver_communications` · `Diver_detection_sonar` · `Diver_down_flag` · `Diver_navigation` · `Diver_organisations` · `Diver_propulsion_vehicle` · `Diver_rescue` · `Diver_training` · `Diver_training_organization` · `Diver_training_standard` · `Diver_trim` · `Divers_Academy_International` · `Divers_Alert_Network` · `Divers_Institute_of_Technology` · `Diversnight` · `Divex` · `Diving_Diseases_Research_Centre` · `Diving_Medical_Advisory_Council` · `Diving_Science_and_Technology` · `Diving_Unlimited_International` · `Diving_activities` · `Diving_air_compressor` · `Diving_bell` · `Diving_chamber` · `Diving_cylinder` · `Diving_disorders` · `Diving_equipment` · `Diving_hazards` · `Diving_helmet` · `Diving_in_Timor-Leste` · `Diving_in_the_Maldives` · `Diving_in_the_Philippines` · `Diving_instructor` · `Diving_mask` · `Diving_medicine` · `Diving_physics` · `Diving_procedures` · `Diving_rebreather` · `Diving_reflex` · `Diving_regulations` · `Diving_regulator` · `Diving_safety` · `Diving_safety_officer` · `Diving_shot` · `Diving_suit` · `Diving_supervisor` · `Diving_support_equipment` · `Diving_support_vessel` · `Diving_team` · `Diving_watch` · `Diving_weighting_system` · `Doing_It_Right_(scuba_diving)` · `Dominic_Landucci` · `Dorothy_Metcalf-Lindenburger` · `Dottie_Frazier` · `Doug_Allan` · `Douglas_H._Wheelock` · `Downline_(diving)` · `Drift_diving` · `Drill_Master_diving_accident` · `Drowning` · `Drug_tolerance` · `Dry_Combat_Submersible` · `Dry_suit` · `Duty_of_care` · `Dynamic_apnea` · `Dysbaric_osteonecrosis` · `Dysbarism` · `E._Lee_Spence` · `E._Yale_Dawson` · `ENOS_Rescue-System` · `Ear_clearing` · `Eduard_Admetlla_i_Lázaro` · `Edward_D._Thalmann` · `Electro-galvanic_oxygen_sensor` · `Elisabeth_Kristoffersen` · `Emergency_ascent` · `Emergency_locator_beacon` · `Emma_Farrell_(freediver)` · `Emma_Hwang` · `Environmental_impact_of_recreational_diving` · `Enzo_Maiorca` · `Equivalent_air_depth` · `Equivalent_narcotic_depth` · `Eric_Cheng` · `Ernest_William_Moir` · `Esbjörn_Svensson` · `Escape_trunk` · `Ethanol` · `Ethylene` · `Eugenie_Clark` · `European_Diving_Technology_Committee` · `European_Underwater_Federation` · `European_Underwater_and_Baromedical_Society` · `FNRS-2` · `FNRS-3` · `Faber_Industrie_S.p.A.` · `Fabien_Cousteau` · `Fatma_Uruk` · `Federación_Española_de_Actividades_Subacuáticas` · `Federazione_Italiana_Attività_Subacquee` · `Felix_Hoppe-Seyler` · `Fenzy` · `Fernando_Garfella_Palmer` · `Finger_Lakes_Underwater_Preserve_Association` · `Finning_techniques` · `Finswimming` · `First_aid` · `Fitness_to_dive` · `Flavia_Eberhard` · `Francis_P._Hammerberg` · `Francisco_Ferreras` · `François_de_Roubaix` · `Fred_M._Roberts` · `Freediving` · `Freediving_blackout` · `Freeflow` · `Frenzel_maneuver` · `Frogman` · `Frogman_Corps_(Denmark)` · `Frédéric_Dumas` · `Fuerzas_Especiales` · `Fukuryu` · `Full-face_diving_mask` · `Fédération_Française_d'Études_et_de_Sports_Sous-Marins` · `GABAA_receptor` · `GRUMEC` · `Garrett_Reisman` · `Gary_Gentile` · `Gas_blending` · `Gas_blending_for_scuba_diving` · `General_anaesthesia` · `George_Bass_(archaeologist)` · `George_F._Bond` · `George_R._Fischer` · `Georges_Beuchat` · `Giovanni_Alfonso_Borelli` · `Global_Explorer_ROV` · `Global_Underwater_Explorers` · `Glossary_of_underwater_diving_terminology` · `Goldfinder` · `Goldfish-class_ROUV` · `Goran_Čolak` · `Gordon_Smith_(inventor)` · `Graham_Balcombe` · `Graham_Jessop` · `Green_Fins` · `Gregory_Chamitoff` · `Guillaume_Néry` · `Guinness_World_Records` · `Gunter_Schöbel` · `Guy_Garman` · `Guybon_Chesney_Castell_Damant` · `Gyrojet` · `HMS_Challenger_(K07)` · `HMS_Royal_George_(1756)` · `Haenyeo` · `Halcyon_PVR-BASC` · `Halcyon_RB80` · `Haldane's_decompression_model` · `Hannes_Keller` · `Hans_Hass` · `Hans_Hass_Award` · `Hawaiian_sling` · `Hazard_analysis` · `Hazmat_diving` · `Health_and_Safety_Executive` · `Heckler_&_Koch_P11` · `Heidemarie_Stefanyshyn-Piper` · `Heinke_(diving_equipment_manufacturer)` · `HeinrichsWeikamp` · `Helgoland_Habitat` · `Helicopter_Aircrew_Breathing_Device` · `Heliox` · [[Helium]] · `Helium_analyzer` · `Helium_release_valve` · `Helix_Energy_Solutions_Group` · `Henry's_law` · `Henry_Fleuss` · `Henry_Valence_Hempleman` · `Henry_Way_Kendall` · `Herbert_Nitsch` · `Hervé_Stevenin` · `Hierarchy_of_hazard_controls` · `High-pressure_nervous_syndrome` · `Hillary_Hauser` · `Hippocrates` · `History_of_Diving_Museum` · `History_of_decompression_research_and_development` · `History_of_scuba_diving` · `History_of_underwater_diving` · `Homer` · `Honor_Frost` · `Hopcalite` · `Hot_stab` · `Hugh_Bradner` · `Human_factors_in_diving_equipment_design` · `Human_factors_in_diving_safety` · `Human_torpedo` · `Hydreliox` · [[Hydrogen]] · `Hydrogen_narcosis` · `Hydrostatic_test` · `Hydrox_(breathing_gas)` · `Hyperbaric_evacuation_and_rescue` · `Hyperbaric_medicine` · `Hyperbaric_nursing` · `Hyperbaric_stretcher` · `Hyperbaric_treatment_schedules` · `Hyperbaric_welding` · `Hypercapnia` · `Hyperoxia` · `Hyperthermia` · `Hypocapnia` · `Hypothermia` · `Hysteria` · `ICD-10` · `ICD-11` · `IDA71` · `Ian_Edward_Fraser` · `Ice_diving` · `Ictineu_3` · `In-water_recompression` · `In-water_surface_cleaning` · `Incident_pit` · `Incompetence` · `Index_of_recreational_dive_sites` · `Index_of_underwater_divers` · `Index_of_underwater_diving` · `Inner_ear_decompression_sickness` · `Innes_McCartney` · `Instinctive_drowning_response` · `International_Association_for_Handicapped_Divers` · `International_Association_of_Nitrox_and_Technical_Divers` · `International_Diving_Regulators_and_Certifiers_Forum` · `International_Diving_Schools_Association` · `International_Life_Saving_Federation` · `International_Marine_Contractors_Association` · `International_Scuba_Diving_Hall_of_Fame` · `International_Submarine_Escape_and_Rescue_Liaison_Office` · `Interspiro_DCSC` · `Introductory_diving` · `Investigation_of_diving_accidents` · `Isobaric_counterdiffusion` · `Israeli_Diving_Federation` · `Ivan_Tors` · `J._B._S._Haldane` · `J._Lamar_Worzel` · `JAGO_(German_research_submersible)` · `JIM_suit` · `Jack_Sheppard_(cave_diver)` · `Jackstay` · `Jacques_Cousteau` · `Jacques_Mayol` · `Jacques_Triger` · `Jagdkommando` · `James_Cameron` · `James_F._Cahill` · `James_Joseph_Magennis` · `James_P._Delgado` · `James_Talacek` · `Jarrod_Jablonski` · `Jason_deCaires_Taylor` · `Jean-Michel_Cousteau` · `Jeanette_Epps` · `Jeffrey_Bozanic` · `Jeffrey_Williams_(astronaut)` · `Jeremy_Hansen` · `Jerónimo_de_Ayanz_y_Beaumont` · `Jessica_Meir` · `Jiaolong_(submersible)` · `Jill_Heinerth` · `Jim_Bowden_(diver)` · `Jim_Jones_(American_football,_born_1935)` · `Joachim_Wendler` · `Job_safety_analysis` · `Jochen_Hasenmayer` · `Joe_Savoie` · `John_Bennett_(diver)` · `John_Bevan_(diver)` · `John_Chatterton` · `John_Christopher_Fine` · `John_D._Craig` · `John_D._Olivas` · `John_Day_(carpenter)` · `John_Deane_(inventor)` · `John_Ernest_Williamson` · `John_Herrington` · `John_Lethbridge` · `John_Mattera` · `John_Morgan_Wells` · `John_Peter_Oleson` · `John_R._Clarke_(scientist)` · `John_Rawlins_(Royal_Navy_officer)` · `John_Scott_Haldane` · `John_Veltri` · `John_Volanthen` · `Johnson_Outdoors` · `Johnson_Sea_Link_accident` · `Jon_Lindbergh` · `Jonathan_Bird` · `Jonathan_Dory` · `Josef_Schmid_(flight_surgeon)` · `Josef_Velek` · `Joseph-Martin_Cabirol` · `Joseph_B._MacInnis` · `Joseph_M._Acaba` · `Joseph_Salim_Peress` · `José_M._Hernández` · `Justin_Brown_(aquanaut)` · `K._Megan_McArthur` · `KOPASKA` · `Kaikō_ROV` · `Karen_Kohanowich` · `Karen_Nyberg` · `Karl_Heinrich_Klingert` · `Karol_Meyer` · `Karst_Underwater_Research` · `Kate_Middleton_(free-diver)` · `Kateryna_Sadurska` · `Kathleen_Rubins` · `Kaşif_ROUV` · `Keith_Jessop` · `Kenneth_William_Donald` · `Kimiya_Yui` · `Kirsty_MacColl` · `Kjell_N._Lindgren` · `Koichi_Wakata` · `Konsul-class_submersible` · `Kronan_(ship)` · [[Krypton]] · `Krzysztof_Starnawski` · `LR5` · `LR7` · `La_Belle_(ship)` · `Lambertsen_Amphibious_Respiratory_Unit` · `Laryngospasm` · `Leigh_Bishop` · `Leni_Riefenstahl` · `Leonardo_D'Imporzano` · `Les_Kaufman` · `Levitation_(physics)` · `Life-support_system` · `Lifting_bag` · `Ligand-gated_ion_channel` · `Limpet_mine` · `Line_marker` · `Lionel_Crabb` · `Lipid` · `Lipid_bilayer` · `List_of_Divers_Alert_Network_publications` · `List_of_diver_certification_organizations` · `List_of_diving_environments_by_type` · `List_of_diving_equipment_manufacturers` · `List_of_diving_hazards_and_precautions` · `List_of_legislation_regulating_underwater_diving` · `List_of_military_diving_units` · `List_of_researchers_in_underwater_diving` · `List_of_signs_and_symptoms_of_diving_disorders` · `List_of_wreck_diving_sites` · `Liv_Philip` · `Liveaboard` · `Lockout–tagout` · `London_Diving_Chamber_Dive_Lectures` · `Louis_Boutan` · `Louis_de_Corlieu` · `Low_impact_diving` · `Loïc_Leferme` · `Luca_Parmitano` · `Luis_Marden` · `Lyons_Maritime_Museum` · `Lyuba_Ognenova-Marinova` · `MARCOS` · `MSM-1` · `Magnesium_torch` · `Man_in_the_Sea_Museum` · `Mandy-Rae_Cruickshank` · `Mania` · `Marc_Reagan` · `Mares_(scuba_equipment)` · `Margaret_Rule` · `Marine_Commandos` · `Marine_Raider_Regiment` · `Marine_construction` · `Marinejegerkommandoen` · `Mark_Ellyatt` · `Mark_Hulsbeck` · `Mark_IV_Amphibian` · `Mark_M._Newell` · `Mark_T._Vande_Hei` · `Martyn_Farr` · `Mary_Bonnin` · `Mary_Rose` · `Master_Scuba_Diver` · `Master_diver_(United_States_Navy)` · `Matthias_Maurer` · `Maurice_Fargues` · `Maurice_Fernez` · `Maximum_operating_depth` · `McCann_Rescue_Chamber` · `Mechanism_of_diving_regulators` · `Media_diving` · `Medical_Subject_Headings` · `Medical_specialty` · `Medical_toxicology` · `Mehgan_Heaney-Grier` · `Membrane_gas_separation` · `Mendel_L._Peterson` · `Mensun_Bound` · `Messenger_line` · `Metre_sea_water` · `Michael_Arbuthnot` · `Michael_Barratt_(astronaut)` · `Michael_Board` · `Michael_C._Barnette` · `Michael_Fincke` · `Michael_L._Gernhardt` · `Michael_López-Alegría` · `Michele_Westmorland` · `Middle_ear_barotrauma` · `Milan_Dufek` · `Military_diving` · `Minedykkerkommandoen` · `Minentaucher` · `Mini_Rover_ROV` · `Mir_(submersible)` · `Mission_31` · `Mk_1_Underwater_Defense_Gun` · `Modulated_ultrasound` · `Molecular_sieve` · `Momsen_lung` · `Monofin` · `Monty_Halls` · `Moon_pool` · `Morse_Diving` · `Motion_sickness` · `Motorised_Submersible_Canoe` · `Muck_diving` · `Muscle_memory` · `Myriam_Seco` · `Mystic-class_deep-submergence_rescue_vehicle` · `NATO_Submarine_Rescue_System` · `NOAA_Diving_Manual` · `NOGI_Awards` · `Namibian_Marine_Corps` · `Natalia_Molchanova` · `Nataliia_Zharkova` · `National_Academy_of_Scuba_Educators` · `National_Association_of_Underwater_Instructors` · `National_Board_of_Diving_and_Hyperbaric_Medical_Technology` · `National_Oceanic_and_Atmospheric_Administration` · `National_Speleological_Society` · `Nausea` · `Nautical_Archaeology_Program` · `Nautical_Archaeology_Society` · `Nautile` · `Nautilus_Productions` · `Naval_Air_Command_Sub_Aqua_Club` · `Naval_Diving_Unit_(Singapore)` · `Naval_Service_Diving_Section` · `Naval_Special_Operations_Command` · `Naval_Submarine_Medical_Research_Laboratory` · `Naval_Support_Activity_Panama_City` · `Navy_diver_(United_States_Navy)` · `Neal_W._Pollock` · `Necker_Nymph` · `Nederlandse_Onderwatersport_Bond` · `Nemrod` · [[Neon]] · `Neurotransmitter_receptor` · `Neutral_Buoyancy_Laboratory` · `Neutral_Buoyancy_Simulator` · `Neutral_buoyancy` · `Neutral_buoyancy_pool` · `Neutral_buoyancy_simulation_as_a_training_aid` · `Neville_Coleman` · `Newtsuit` · `Nicholas_Mevoli` · `Nicholas_Patrick` · `Nicole_Stott` · `Night_diving` · `Nikonos` · [[Nitrogen]] · `Nitrous_oxide` · `Nitrox` · `No-limits_apnea` · [[Noble_gas]] · `Noel_Monkman` · `Non-freezing_cold_injury` · `Nondestructive_testing` · `Nordic_Deep` · `Norishige_Kanai` · `Nuno_Gomes_(diver)` · `Occupational_safety_and_health` · `Ocean_current` · `Oceanic_Worldwide` · `Octopus_wrestling` · `Offshore_construction` · `Open-water_diving` · `OpenROV` · `Open_Water_Diver` · `Operational_Diving_Division_(SA_Navy)` · `Operations_manual` · `Opiate` · `Orinasal_mask` · `Oscar_Gugen` · `Outline_of_recreational_dive_sites` · `Outline_of_underwater_divers` · `Outline_of_underwater_diving` · `Overconfidence_effect` · `Overlearning` · [[Oxygen]] · `Oxygen_compatibility` · `Oxygen_therapy` · `Oxygen_toxicity` · `Oxygen_window` · `Panic` · `Paranoia` · `Partial_pressure` · `Pascal_Bernabé` · `Patrick_Musimu` · `Paul_Bert` · `Paul_Hill_(flight_director)` · `Paul_Rose_(TV_presenter)` · `Pearl_hunting` · `Pearling_in_Western_Australia` · `Pedro_Duque` · `Peggy_Whitson` · `Penetration_diving` · `Peppo_Biscarini` · `Performance_Freediving_International` · `Pete_Oxford` · `Peter_B._Bennett` · `Peter_Gimbel` · `Peter_Kreeft_(diver)` · `Peter_Scoones` · `Peter_Throckmorton` · `Philippe_Cousteau` · `Philippe_Diolé` · `Philippe_Tailliez` · `Physiology_of_decompression` · `Pierre-Marie_Touboulic` · `Pierre_Frolla` · `Pierre_Petit_(photographer)` · `Pigging` · `Pilar_Luna` · `Pisces-class_deep_submergence_vehicle` · `Polespear` · `Police_diving` · `Pony_bottle` · `Porpoise_(scuba_gear)` · `Potable_water_diving` · `PowerSwim` · `Powerhead_(firearm)` · `Pressure_swing_adsorption` · `Pressure_washing` · `Priz-class_deep-submergence_rescue_vehicle` · `Professional_Association_of_Diving_Instructors` · `Professional_Diving_Instructors_Corporation` · `Professional_Technical_and_Recreational_Diving` · `Professional_diving` · `Public_safety_diving` · `Pyle_stop` · `QBS-06` · `Queen_Anne's_Revenge` · `Quintana_Roo_Speleological_Survey` · `R-2_Mala-class_swimmer_delivery_vehicle` · `RMS_Lusitania` · `ROV_KIEL_6000` · `ROV_PHOCA` · `RV_Calypso` · `Raid_on_Alexandria_(1941)` · `Ramón_Bravo` · `Randolph_Bresnik` · `Ratio_decompression` · `Rebreather_Association_of_International_Divers` · `Rebreather_diving` · `Receptor_antagonist` · `Recreational_Dive_Planner` · `Recreational_dive_sites` · `Recreational_diver_course_referral` · `Recreational_diver_training` · `Recreational_diving` · `Recreational_scuba_certification_levels` · `Reduced_gradient_bubble_model` · [[Redundancy_(engineering)]] · `Reef_Check` · `Reef_Life_Survey` · `Reflex` · `Reid_Wiseman` · `Remotely_operated_underwater_vehicle` · `René_Cavalero` · `Rescue_Diver` · `Rex_J._Walheim` · `Ric_Frazier` · `Ricardo_Armbruster` · `Richard_Harris_(anaesthetist)` · `Richard_Pyle` · `Richard_R._Arnold` · `Richie_Kohler` · `Rick_Stanton` · `Risk_assessment` · `Risk_control` · `Risk_management` · `Rob_Stewart_(filmmaker)` · `Robert_A._Barth` · `Robert_Ballard` · `Robert_Boyle` · `Robert_Croft_(diver)` · `Robert_F._Marx` · `Robert_Sheats` · `Robert_Sténuit` · `Robert_Thirsk` · `Robert_William_Hamilton_Jr.` · `Robin_Cook_(American_novelist)` · `Rodney_Fox` · `Ron_Taylor_(diver)` · `Ronald_J._Garan_Jr.` · `Royal_Australian_Navy_School_of_Underwater_Medicine` · `Royal_Engineers` · `Royal_Navy_ships_diver` · `Rubicon_Foundation` · `Rule_of_thirds_(diving)` · `Russian_commando_frogmen` · `Russian_deep_submergence_rescue_vehicle_AS-28` · `Russian_submarine_AS-34` · `Russian_submarine_Losharik` · `SEALAB` · `SEAL_Delivery_Vehicle` · `SJT-class_ROUV` · `SNOMED_CT` · `SP-350_Denise` · `SPP-1_underwater_pistol` · `SRV-300` · `SS_Commodore` · `SS_Egypt` · `SS_Laurentic_(1908)` · `Safety-critical_system` · `Safety_data_sheet` · `Salt_water_aspiration_syndrome` · `Salvage_diving` · `Samir_Alhafith` · `Sandra_Magnus` · `Sappers_Divers_Group` · `Sara_Campbell` · `Satoshi_Furukawa` · `Saturation_diving` · `Saturation_diving_system` · `Save_Ontario_Shipwrecks` · `Science_of_underwater_diving` · `Scientific_diving` · `Scorpio_ROV` · `Scott_Carpenter` · `Scott_Carpenter_Space_Analog_Station` · `Scott_Kelly_(astronaut)` · `Scuba_Diving_International` · `Scuba_Educators_International` · `Scuba_Schools_International` · `Scuba_cylinder_valve` · `Scuba_diving` · `Scuba_diving_fatalities` · `Scuba_diving_in_the_Cayman_Islands` · `Scuba_diving_therapy` · `Scuba_diving_tourism` · `Scuba_gas_management` · `Scuba_gas_planning` · `Scuba_manifold` · `Scuba_set` · `Scuba_skills` · `SeaKeys` · `SeaPerch` · `Sea_Dragon-class_ROV` · `Sea_Pole-class_bathyscaphe` · `Sea_Research_Society` · `Seabed_mining` · `Seabed_tractor` · `Seafox_drone` · `Sedative` · `Semipermeable_membrane` · `Serena_Auñón-Chancellor` · `Shadow_Divers` · `Shallow_Water_Combat_Submersible` · `Shannon_Walker` · `Shark_tourism` · `Shayetet_13` · `Shearwater_Research` · `Sheck_Exley` · `Ships_husbandry` · `Sidemount_diving` · `Siebe_Gorman` · `Siebe_Gorman_CDBA` · `Siebe_Gorman_Salvus` · `Silica_gel` · `Silt_out` · `Siluro_San_Bartolomeo` · `Simon_Mitchell` · `Simone_Arrigoni` · `Simone_Melchior` · `Single_point_of_failure` · `Sinking_of_MV_Conception` · `Sinking_of_the_Rainbow_Warrior` · `Sinking_ships_for_wreck_diving_sites` · `Situation_awareness` · `Skandalopetra_diving` · `Skill_assessment` · `Snorkel_(swimming)` · `Snorkeling` · `Snuba` · `Society_for_Underwater_Historical_Research` · `Society_for_Underwater_Technology` · `Solo_diving` · `Sonar` · `South_African_Underwater_Sports_Federation` · `South_Pacific_Underwater_Medicine_Society` · `Space_Systems_Laboratory_(Maryland)` · `Spearfishing` · `Speargun` · `Special_Actions_Detachment` · `Special_Air_Service` · `Special_Air_Service_Regiment` · `Special_Boat_Service` · `Special_Boat_Squadron_(Sri_Lanka)` · `Special_Forces_Command_(Turkey)` · `Special_Forces_Group_(Belgium)` · `Special_Operations_Battalion_(Croatia)` · `Special_Service_Group_(Navy)` · `Special_Warfare_Diving_and_Salvage` · `Sponge_diving` · `Sport_diving_(sport)` · `Stan_Waterman` · `Standard_diving_dress` · `Standard_operating_procedure` · `Star_Canopus_diving_accident` · `Static_apnea` · `Steinke_hood` · `Stena_Seaspread_diving_accident` · `Stephanie_Schwabe` · `Stephen_Frink` · `Stephen_Keenan` · `Steve_Chappell` · `Steve_Irwin` · `Steve_Lewis_(diver)` · `Steve_Parish_(photographer)` · `Steve_Squyres` · `Stig_Severinsen` · `Stimulus_(physiology)` · `Stress_exposure_training` · `Stéphane_Mifsud` · `Sub-Aqua_Association` · `Sub_Marine_Explorer` · `Submarine_Escape_Immersion_Equipment` · `Submarine_Escape_Training_Facility_(Australia)` · `Submarine_Escape_and_Rescue_system_(Royal_Swedish_Navy)` · `Submarine_Products` · `Submarine_Rescue_Diving_Recompression_System` · `Submarine_escape_training_facility` · `Submarine_pipeline` · `Submarine_rescue` · `Submarine_rescue_ship` · `Subskimmer` · `Substance-induced_psychosis` · `Sunita_Williams` · `Supervised_diver` · `Surface-supplied_diving` · `Surface-supplied_diving_equipment` · `Surface-supplied_diving_skills` · `Surface_marker_buoy` · `Surfer's_ear` · `Sustained_load_cracking` · `Suunto` · `Swedish_warship_Mars` · `Swietenia_Puspa_Lestari` · `Swimfin` · `Swimming-induced_pulmonary_edema` · `Swimming_at_the_1900_Summer_Olympics_–_Men's_underwater_swimming` · `Sydney_Knowles` · `Sylvia_Earle` · `Syndrome` · `T1200_Trenching_Unit` · `Tactical_Divers_Group` · `Takuya_Onishi` · `Tamara_Benitez` · `Tanya_Streeter` · `Tara_Ruttley` · `Taravana` · `Task_loading` · `Teaching_method` · `Technical_Diving_International` · `Technical_diving` · `Ted_Eldred` · `Tektite_habitat` · `Teseo_Tesei` · `Testing_and_inspection_of_diving_cylinders` · `Thalmann_algorithm` · `Tham_Luang_cave_rescue` · `The_Darkness_Beckons` · `The_Diver` · `The_Last_Dive` · `The_Silent_World:_A_Story_of_Undersea_Discovery_and_Adventure` · `Theories_of_general_anaesthetic_action` · `Thermal_balance_of_the_underwater_diver` · `Thermal_lance` · `Thermodynamic_model_of_decompression` · `Thomas_Marshburn` · `Thomas_Pesquet` · `Tim_Peake` · `Timeline_of_diving_technology` · `Timothy_Creamer` · `Timothy_J._Broderick` · `Timothy_Kopra` · `Tom_Mount` · `Tom_Sietas` · `Torricellian_chamber` · `Towboard` · `Tremie` · `Trevor_Hampton` · `Trevor_Jackson_(diver)` · [[Trimix_(breathing_gas)]] · `Trimix_Scuba_Association` · `Turkish_Underwater_Sports_Federation` · `U.S._Navy_Diving_Manual` · `UNGERIN` · `URF_(Swedish_Navy)` · `USS_Monitor` · `US_Navy_decompression_models_and_tables` · `Umberto_Pelizzari` · `Uncontrolled_decompression` · `Undersea_and_Hyperbaric_Medical_Society` · `Underwater_Archaeology_Branch,_Naval_History_&_Heritage_Command` · `Underwater_Bike_Race` · `Underwater_Construction_Teams` · `Underwater_Demolition_Command` · `Underwater_Demolition_Team` · `Underwater_Escape_Training_Unit` · `Underwater_Hockey_World_Championships` · `Underwater_Orienteering_World_Championships` · `Underwater_Rugby_World_Championships` · `Underwater_Society_of_America` · `Underwater_acoustic_communication` · `Underwater_acoustic_positioning_system` · `Underwater_acoustics` · `Underwater_archaeology` · `Underwater_breathing_apparatus` · `Underwater_computer_vision` · `Underwater_construction` · `Underwater_cutting_and_welding` · `Underwater_cycling` · `Underwater_demolition` · `Underwater_diving` · `Underwater_diving_emergency` · `Underwater_diving_environment` · `Underwater_diving_in_Guam` · `Underwater_domain_awareness` · `Underwater_environment` · `Underwater_exploration` · `Underwater_firearm` · `Underwater_football` · `Underwater_habitat` · `Underwater_hockey` · `Underwater_hockey_in_Australia` · `Underwater_hockey_in_Turkey` · `Underwater_logging` · `Underwater_orienteering` · `Underwater_photography` · `Underwater_photography_(sport)` · `Underwater_rugby` · `Underwater_rugby_in_the_United_States` · `Underwater_search_and_recovery` · `Underwater_searches` · `Underwater_sports` · `Underwater_survey` · `Underwater_target_shooting` · `Underwater_vehicle` · `Underwater_videography` · `Underwater_vision` · `Underwater_work` · `United_Diving_Instructors` · `United_States_Marine_Corps_Combatant_Diver_Course` · `United_States_Marine_Corps_Force_Reconnaissance` · `United_States_Marine_Corps_Reconnaissance_Battalions` · `United_States_Navy_Experimental_Diving_Unit` · `United_States_Navy_SEALs` · `United_States_military_divers` · `Valerie_Taylor_(diver)` · `Valerie_van_Heest` · `Valsalva_maneuver` · `Van_der_Waals_force` · `Varying_Permeability_Model` · `Vasa_(ship)` · `Vertical_Blue` · `Victor_Berge` · `VideoRay_UROVs` · `Vintage_scuba` · `Waage_Drill_II_diving_accident` · `Wall_diving` · `Walter_Steyn` · `Water_polo_cap` · `Water_safety` · `Water_surface_searches` · `Welfreighter` · `Western_Norway_University_of_Applied_Sciences` · `Wet_Nellie` · `Wet_sub` · `Wetsuit` · `Whydah_Gally` · `Wildrake_diving_accident` · `Willard_Franklyn_Searle` · `Willful_violation` · `William_Beebe` · `William_Hogarth_Main` · `William_Paul_Fife` · `William_R._Royal` · `William_Stone_(caver)` · `William_Trubridge` · `Women_Divers_Hall_of_Fame` · `Woodville_Karst_Plain_Project` · `Work_of_breathing` · `World_Recreational_Scuba_Training_Council` · `Wreck_diving` · [[Xenon]] · `YMCA_SCUBA_Program` · `Yasemin_Dalkılıç` · `Yuri_Gagarin_Cosmonaut_Training_Center` · `Yves_Le_Prieur` · `Zale_Parry` · `Émile_Gagnan` · `Épaulard` · `Şahika_Ercümen` ## From the vault media library !Nitrogen narcosis thumb.png *Nitrogen Narcosis — from the vault's own media holdings, placed 2026-07-09. MTN / Wikitube.io original · CC BY-SA 4.0.* <!-- LOCAL-MEDIA-PASS:END --> > **Room:** [[Helium]] · **Status:** ✅ shipped ## Overview Nitrogen narcosis is a reversible alteration of consciousness produced by breathing nitrogen at elevated partial pressure, principally encountered by underwater divers using compressed air below roughly 30 metres (100 feet). First systematically characterised by US Navy researchers Behnke, Thomson, and Motley in 1935, the condition presents as euphoria, impaired reasoning, narrowed attention, slowed reaction time, and motor incoordination — symptoms qualitatively resembling alcohol intoxication, which inspired Albert Behnke's "Martini's law": each additional 15 metres (50 feet) of depth on air produces an effect roughly equivalent to one dry martini. The mechanism is described by the Meyer–Overton correlation: narcotic potency of inert gases scales with their lipid solubility (oil/gas partition coefficient), implicating perturbation of neuronal membranes or membrane-bound ion channels. Nitrogen's relatively high lipid solubility makes it modestly narcotic; argon and xenon are stronger; helium, with very low lipid solubility, is essentially non-narcotic at diving depths. This contrast is the operational reason commercial saturation, technical, and military deep divers substitute helium–oxygen (heliox) or helium–nitrogen–oxygen (trimix) breathing gases below approximately 50–60 metres. Onset is rapid on descent and reversal is equally rapid on ascent; no residual neurological deficits are recognised. Quantitatively, the narcotic dose is proportional to the inspired partial pressure of nitrogen, pN₂ ≈ FN₂ × Pambient, where Pambient (in bar) increases by one per ten metres of seawater. Nitrogen narcosis remains a leading cause of recreational diving accidents and a foundational topic in undersea and hyperbaric [[Medicine|medicine]]. ## See also - Room hub: [[Helium]] - p5.js Editor conventions: P5 JS EDITOR - Wiki root: MAIN --- *Scaffolded by `generative-microsim` from row 69 of the Helium sheet on 2026-05-12T05:22:16Z.* <!-- LOCAL-MEDIA-PASS:START --> <!-- CRAFT-LINK:START g12 --> *Built to the [[WT!P5_js_Microsim_Master_Class|p5.js Master Class]].* <!-- CRAFT-LINK:END --> ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Nitrogen_narcosis) : [Wikitube](https://en.wikitube.io/wiki/Nitrogen_narcosis) ## Previous hub tags Tree parent: [[Helium]]. Legacy hubs: none. --- *Sources: 1 legacy note. Minted wave 1, 2026-07-30 (v1.6 order).*