Nav Rules: COLREGS Exam Prep

Rules of the Road is the module that fails people. It is closed book, it is usually graded at 90%, and the International and Inland texts differ in ways that are easy to mix up under time pressure. This app is built for that one problem.

1,200 questions. The full rule text, 52 chapters. Completely offline.

WHAT YOU GET
• 1,200 multiple-choice questions covering International, Inland, and questions that apply to both
• 83 original vector diagrams for lights, shapes and vessel encounters — tap any one for full screen, pinch to zoom
• The complete rule text in 52 chapters, with International and Inland shown side by side so you can see exactly where the two diverge
• 54 further figures inside the rule text itself
• Full-text search across every rule and every question

PRACTICE THE WAY YOU ACTUALLY STUDY
Filter by zone — International, Inland, or both. Filter by topic: lights and shapes, sound and light signals, steering and sailing, restricted visibility, general definitions, distress, annexes, inland-specific. Or filter by where you stand: unseen, previously missed, bookmarked, or due for review today.

Answers are graded the moment you tap. Many questions link straight through to the rule sections that may be relevant, so you can go read the actual text instead of memorizing an answer.

EXAM MODE
Choose the question count and zone, start the timer, and get no feedback at all until you submit — the way the real thing works. The results page gives you your score against the 90% line, your misses grouped by topic, and every question available for review. Answer choices are reordered wherever the wording allows, so you can never fall back on remembering a position.

REMEMBER IT UNTIL TEST DAY
A spaced-repetition queue schedules each question to come back just before you would have forgotten it. Missed questions stay in the missed list until you have answered them correctly and consistently. Bookmark anything you want to return to.

KNOW WHERE YOU STAND
A readiness dial estimates your score for each zone. A topic heatmap shows which areas are weak. Per-rule accuracy tells you which specific rule to go reread. Streaks, total questions answered, and average time per question are all tracked.

BUILT FOR HOW MARINERS STUDY
• 100% offline. No signal needed, ever — it works at sea, at the dock, and in the yard.
• No account and no sign-up
• No ads, no subscription, no in-app purchases. One purchase and it is yours.
• Optional iCloud sync keeps your progress in step across iPhone and iPad
• Dark appearance by default, plus an extra font size step above the system setting for anyone who wants larger type

WHO IT IS FOR
Candidates for OUPV (six-pack), Master under 100 tons, and Mate/Master at every level. Academy and maritime school students working through the rules alongside coursework. Boat owners who simply want to understand what the lights ahead of them mean.

A NOTE ON ACCURACY
Rule text is reproduced from the published navigation rules. The links between a question and a rule are suggestions to help you find the relevant passage — the rule text itself is the authority, and the app words it that way rather than pretending otherwise.

This app is an independent study aid. It is not affiliated with, endorsed by, or an official publication of the U.S. Coast Guard or the National Maritime Center.