60 interactive laboratories across 8 subjects, in place of chapters. Every number on screen is computed by a deterministic engine and defensible on the spot — including the triangle turning beside this sentence, which is solved, not drawn.
These run entirely in your browser. They are not videos and they are not mock-ups. Drag anything and the numbers recompute.
A clean radar screen is not the same thing as an empty sea. There is a GRP yacht on your starboard beam at a mile, with no radar reflector hoisted — four square metres of echo, where the ship ahead of you returns ten thousand. Now tidy the picture up.
Every echo above is the output of a detection calculation — the radar range equation against a sea-clutter model, with your own controls in the path. Nothing is drawn because it ought to be visible. Panels of RA-01; the full laboratory adds beam width, pulse length, the false-echo catalogue and the IMO performance standard the set has to meet.
Start freeMove your ship around the centre and watch which semicircle you are in, and what that means you should do about it.
This is one panel of MT-05. The full laboratory has the track, the semicircles, the 1-2-3 rule and the avoiding action.
Start freeAir is pushed from high pressure towards low — that force is real and it never stops. Yet the wind on every weather chart you will ever see runs along the isobars, not across them. Here is why.
This is one panel of MT-01. Set the latitude to zero and the lab refuses to give you a wind, because at the equator there is not one.
Start freeThe mean sun, the apparent sun and the stars all keep different time. Pick a town and a moment, and watch the three hands separate.
Every figure here comes from the platform’s own engine — the same Julian date, the same ΔT model, the same equation of time. Panels of ES-02 and ES-03.
Start freeType your town — Burdwan, Kolkata, Katihar, anywhere — pick a time in GMT or LMT, and your sky opens: constellations in colour, the Sun, the Moon, the planets, and the horizons that frame them. Then the sextant, the corrections, the PZX triangle, and star sights worked to a fix.
13 laboratories →
Its own written paper, and the half of navigation you use every watch: the sailings on a Mercator chart whose stretched latitudes make a rhumb line straight, coastal fixes with the cocked hat opening as a compass error creeps in, the tide under the keel, and the current solved as one vector triangle drawn three ways.
6 laboratories →
The subject candidates most often fail, and the one a book helps least with — because the Rules are not a list to recite, they are a decision about a situation that is changing while you make it. Examined in the oral, as Function I.
3 laboratories →
A separate mandatory simulator course and a separate certificate. An operable display where every echo is the output of a detection calculation rather than a drawing — and the tolerance that lets a compliant ARPA be two miles wrong about CPA after one minute.
2 laboratories →
Read the weather, and route the ship around it. Why the Coriolis force makes wind blow ALONG the isobars, what DALR and SALR decide about the sky above you — and the one that matters most, the tropical revolving storm.
6 laboratories →
K, B, M and G — the four letters that keep her upright. From the shape of the hull to the storm, and on to the damaged ship: floodable length, the margin line, and the heavy-weather rolling that has no warning.
11 laboratories →
Stow her full, keep her safe, prove it with numbers — trade by trade. The general hold, the box trade, the bulk trade, the tanker and the gas carrier.
10 laboratories →
The night sky, explained by playing with it. For every curious mind — no exams at this door.
8 laboratories →
The dry adiabatic lapse rate reads 9.76 °C per kilometre because the engine divides gravity by the specific heat of air, not because someone looked it up.
Where the software uses an approximation, it says which one and how wrong it is. The plane-chart approximation used for coastal fixes is out by 0.3 metres at 12°N and 4.4 metres at 51°N, and the lab tells you so.
Where no answer exists, it refuses. Squeeze the isobars around a high tightly enough and there is no wind that balances — so the lab says that, instead of printing a plausible number.
Many of those cases compute the same quantity twice, by genuinely different methods, and require the two to agree.
Syllabus coverage you can check line by line, enrolment for your cadets, and a faculty console that shows who is stuck before the exam does.
Thirty days, everything unlocked, no card. Works offline once it has loaded, which matters when you are reading this on a ship.
The astronomy door is open to everyone, has no exam attached, and is the reason this product has a soul.
A cadet or a serving officer starts free and is inside a laboratory in a minute. A college talks to us first, because enrolment and faculty tools need setting up properly.