Free interactive sailing theory
Learn the sea
by doing.
A full ladder of theory courses — first steps to Yachtmaster Ocean — taught with 66 hands-on trainers, worked examples computed live by a real navigation engine, and an AI tutor on every lesson. Not a PDF in sight.
- courses
- 11courses
- lessons
- 100lessons
- trainers
- 66trainers
- questions
- 338questions
One ladder, first sail to first ocean
Every course draws on one pool of lessons and trainers — progress carries between them. Syllabus mappings are factual; not affiliated with or endorsed by the RYA.
Essential Navigation & Seamanship
FREE17 lessons
Day Skipper theory
£19.9934 lessons
Coastal Skipper / Yachtmaster Offshore theory
£19.9916 lessons
Marine radio (SRC prep)
£9.996 lessons
CEVNI — inland waterways signs
FREE4 lessons
Radar for small craft
£9.995 lessons
Marine diesel engine
£9.997 lessons
Yachtmaster Ocean theory (astro)
£19.9910 lessons
Sea survival
FREE4 lessons
First aid afloat
FREE4 lessons
Sextant mastery
£9.9915 lessons
Hover to pause · four courses free · everything for £49.99
Stuck mid-lesson? Ask.
Every lesson and the trainers page carry a tutor that answers from the courses themselves — ask anything from “why are springs bigger?” to “why do we swing the arc?” and get the exact passages that teach it, linked to their lessons. No hallucinated seamanship: if the courses don’t cover it, the tutor says so.
Want a conversation? Sign in for smart answers, or run a small AI entirely on your own device — either way the sources are always shown, and the lessons stay the authority.
Try it in a free lesson →Eleven theory courses
First steps to Yachtmaster Ocean — plus radio, radar, CEVNI, the diesel engine, survival, first aid and our own sextant-mastery course. Pick what you’re studying for; progress follows you.
Open →Learn by doing66 interactive trainers
Orbit a 3D ship at night, take a noon sight, solve a tidal gate, read a GZ stability curve, bleed a diesel, work a real VHF faceplate.
Open →Live examplesA real navigation engine
Every worked example computed live — tides, streams, course to steer, compass ladders, celestial sights. New numbers on demand, workings shown.
Open →ChartworkYour own training chart
An original, RYA-style chart derived from one mathematical seabed — print the A3 PDF, work the 32-question chart paper, or generate a fresh one.
Open →Passage plannerPlan real passages
The full RYA method on an interactive chart — tidal heights, hourly streams, CTS per leg, every step of the working visible.
Open →RevisionNotes, quizzes & glossary
338 questions across every topic, timed papers, your own revision notes (Anki export), and a full glossary — every new term defined on first meeting.
Open →