Clewed Up

Sailing navigation theory

Theory that sticks before you slip the lines.

Illustrated lessons, instant-feedback revision and timed mock exams for Essential Navigation, Day Skipper and Coastal Skipper / Yachtmaster Offshore theory.

Open the trainer Install on your phone

Free to use in your browser. Works offline once opened. App Store and desktop versions are on the way.

Day Skipper · Nautical terms7 / 20

An object “abeam” of your boat is:

  • ADirectly ahead of the bow
  • BAt 90° to the centreline
  • CAbout 45° on the bow
  • DDirectly astern

Correct. Abeam is at right angles to the fore-and-aft line. “Abaft the beam” means further aft than abeam; “on the quarter” means between abeam and right astern.

Three syllabi, one trainer

From your first chart to offshore passage planning.

Pick a level, choose your topics and decide how you want to work. Or mix all three for a warm-up before a practical course.

Level 1

Essential Navigation & Seamanship

Charts, buoyage, tidal awareness, rules of the road, anchoring, forecasts and simple passage planning.

62 questions
Level 2

Day Skipper Theory

Chartwork, tidal heights and streams, IRPCS lights and shapes, meteorology, safety and pilotage.

76 questions
Level 3

Coastal Skipper / Yachtmaster Offshore

Advanced position fixing, compass error, tidal anomalies, electronic navigation, weather systems and the full IRPCS.

74 questions

How it works

Learn it, revise it, then test it.

Learn

41 illustrated lessons: buoy galleries, light diagrams, chartwork constructions and weather charts, with key points and a summary.

Revise

Multiple choice with instant feedback and a clear explanation after every answer, so it works as a teaching aid as well as a quiz.

Test

Exam conditions, optionally timed at a minute per question, marked at the end with a topic-by-topic breakdown.

Knots and ropework

Step-by-step knot illustrations, each linked to a demonstration video from Solent Boat Training.

Works offline

Open it once and it keeps working with no signal, which is handy on the water.

Built for instructors too

Instructor notes flag common mistakes, so you can use it in the classroom or set it as homework.

Install it today

Put Clewed Up on your home screen.

No app store needed yet. Install it straight from your browser and it opens full screen, like any other app.

iPhone and iPad

  1. Open the trainer in Safari.
  2. Tap the Share button.
  3. Choose “Add to Home Screen”.

Android

  1. Open the trainer in Chrome.
  2. Tap the ⋮ menu.
  3. Choose “Install app” or “Add to Home screen”.

Windows and Mac

  1. Open the trainer in Chrome or Edge.
  2. Click the install icon in the address bar.
  3. It opens in its own window from then on.

Ready to brush up before your course?

Start with a 20-question revision round at your level. No account, no sign-up.

Open the trainer