Visual learning for divers
From the surface to the silt line.
Interactive tools, math-honest calculators, and depth-true visuals — across recreational, technical, sidemount, and cave diving.
01 · 0–30 m
Recreational.Sporttauchen
Open water through rescue. No-decompression diving on air or nitrox. Where most divers spend their careers.
TL;DR
At 30 m on air, your no-decompression limit is roughly 20 minutes. Switch to EAN32 and that grows to ~30 minutes — with a hard MOD of 33.8 m at PpO₂ 1.4.
Physics · Boyle's law
Gas volume halves at 10 m, thirds at 20 m, quarters at 30 m. Every breath you take at depth costs more than it does at the surface — the foundation of gas planning.
Nitrox planner
MOD · END · best-mix · CNS%
SAC / RMV calculator
Compute from a logged dive · project consumption
NDL lookup
Air, EAN32, EAN36 · agency selector
02 · 30–60 m
Technical.Tek-Tauchen
Decompression begins. Trimix replaces air. Stage cylinders, gas switching, gradient factors — diving becomes math.
TL;DR
Past ~40 m, narcosis significantly impairs judgment; on air, PpO₂ reaches the recreational MOD (1.4) at ~56 m. Helium-based mixes lower both PpO₂ and narcotic depth — at the cost of tripling your gas-planning complexity.
Physics · Tissue saturation
Bühlmann ZH-L16C tracks 16 theoretical tissue compartments. Gradient factors (GF-Lo / GF-Hi) scale how aggressively you offgas — 30/70 conservative, 40/85 baseline.
Deco schedule visualizer
Bühlmann ZH-L16C · GF tunable · stop ladder
Trimix MOD & END
PpO₂ + narcotic depth · best-mix solver
Rock-bottom / minimum gas
Two divers · ascent · conservative reserve
03 · 60–100 m
Deep Tech.Tieftauchen
Mixed-gas diving on open circuit and rebreathers. The twilight zone — where back-gas oxygen drops to 15 % and your travel and deco gases multiply.
TL;DR
At 80 m, an air mix would deliver PpO₂ ~1.9 — toxic. Trimix 15/55 keeps PpO₂ at 1.35 and END (narcotic depth) near 30 m. The gas math is non-negotiable; the deco is hours, not minutes.
Physics · The gas matrix
A 90-minute trimix dive runs four cylinders: back gas, travel, deco, oxygen. Each has a switch depth, an MOD, and a CNS clock. Plan it on land or don't go.
Trimix planner
Best-mix · gas matrix · partial-pressure blending
CCR loop diagram
Interactive · click components for function
CNS% & OTU tracker
Surface intervals · multi-day load
04 · Overhead
Cavern & Cave.Höhlentauchen
No direct path to the surface. Continuous guideline. Redundant gas. Three lights. The unforgiving discipline — where every protocol exists because someone already died without it.
TL;DR — The Five Don'ts
Per NSS-CDS accident analysis: don't dive caves without training, without a continuous guideline, beyond your gas plan (rule of thirds), beyond your depth limit, or with fewer than three lights. Every fatality maps to violating at least one.
Protocol · Continuous guideline
Primary tie-off in daylight. Secondary inside the entrance. Unbroken line to the team's exit. Direction arrows always pointing toward fresh air. Personal cookies mark your team's turn-around.
Cave line protocol
Primary · secondary · jumps · gaps
Lost-line decision tree
Search pattern · reel deployment · team comms
Hand signals reference
Rec · tech · cave — printable bundle