Tools
Dive physics, made playable.
Little interactive toys for the ideas that run underneath every dive. Drag the sliders, break the intuition, see why the numbers behave the way they do. They're built for understanding, not training — each one says so, and points you to the real experts. They also assume an "average" human body — and you have never met one. The physics is exact; the body it acts on never is. Every one is a falsifiable bet about the water: a piece of math, put where reality can prove it wrong.
Pressure & gas lawsHow depth squeezes and stacks the gas you breathe4
The bubble problem
Boyle's law you can drag. Watch a bubble's gas vanish with depth while its width barely moves — and learn why the last few metres of an ascent matter most.
Open toolHow hard the water pushes
Pascal's law: one atmosphere every 10 metres, hundreds of pounds of force at depth — and why you still aren't crushed. Pick a depth and feel the squeeze.
Open toolEvery breath, taken apart
Dalton's law in action: pick a gas mix and a depth, and watch each gas's pressure climb — why oxygen has a depth ceiling and Nitrox trades bottom time for it.
Open toolWhat dissolves, and what fizzes
Henry's law and the soda-can in your blood: nitrogen dissolves under pressure, then fizzes out if you surface too fast. The physics behind ascending slowly.
Open toolBuoyancy & moving through waterStaying neutral, trimmed, and pointed the right way3
Float, sink, or hang
Archimedes' tug-of-war. Add lead, change suits, switch to salt water, breathe in and out — and see why staying neutral is a constant adjustment.
Open toolGlide like an airplane, not a rocket
Why a flat glide and a slow frog kick cost the least air — and stir the bottom the least. Tilt the diver, switch the kick, and watch the silt rise or settle.
Open toolCrossing a current
Relative velocity you can drag. Set a current and your swim speed, and the tool solves the angle to aim upstream — or tells you the current has already won.
Open toolLight, colour & soundHow the senses get fooled underwater3
Where the colors go
Why red vanishes a few metres down and the deep looks blue. Drag through the depths, watch the spectrum drain, then switch on a dive light and bring it all back.
Open toolWhy everything looks closer
Snell's law at your mask: light bends crossing into your air pocket, so objects look about a third bigger and a quarter nearer. See the fish you'd swear you saw.
Open toolWhy you can't tell where a sound comes from
Your ears find direction from a tiny time gap. Sound moves ~4× faster underwater and runs through your skull — so the gap collapses and a boat seems to come from everywhere.
Open toolThe diving bodyNitrogen in the tissues, heat and cold, and the work of breathing5
How nitrogen soaks in — and out
Sixteen tissues, each chasing the inspired nitrogen on its own clock. Watch them load fast and slow — and see why saturation is harmless but leaving too quickly is not.
Open toolHow fast you breathe a tank
Work out your surface air consumption from a single dive — and untangle the psi/min number (tied to your tank) from the volume RMV that travels to any cylinder.
Open toolBreathing soup
Gas gets denser with depth — four times as thick at 30 m — so every breath is more work and CO₂ creeps up. See why the density limit lands near the air limit, and why the fix is helium, not nitrox.
Open toolHeat, blood flow, and the gas you carry
Why a hot shower or a failed drysuit heater can bite: warm a body still loaded with nitrogen and it holds less, and the surplus can fizz. Temperature, blood flow, and the what-ifs.
Open toolWhere your heat goes
Water pulls heat ~25× faster than air, so your body runs a hidden budget — close the skin, then shiver — to hold 37°. The trap: your core stays put until the budget is spent. Read the reserve, not the thermometer.
Open toolMore on the way — there's no shortage of physics down there to play with.