Master-Nav1.50 - App Store

Master-Nav is a progressive COLREGS learning system developed by a Master Mariner. The COLREGS are notoriously difficult to learn and retain - Master-Nav makes it significantly easier through an interactive system built around how your brain actually works.

Instead of guessing through random question banks, Master-Nav guides you step by step through every rule from start to finish. Wrong answers are revisited until the rules stick - properly.

Complex regulations are broken down into learnable chunks - bite-sized sections supported by mnemonics, memory aids and interactive visuals designed around how the brain actually retains information.

Every incorrect answer is shown graphically alongside the correct one - immediately clear, no confusion. And with a single tap, the relevant COLREGS rule is accessible from any question at any time.

Master-Nav covers COLREGS Parts A to D - General, Steering & Sailing, Lights & Shapes and Sound & Light Signals - plus Annex IV Distress Signals. Over 1000 questions in multiple formats, with a dedicated Practice Section that tracks right, wrong and unanswered so you always know where to focus.

COLREGS - the easy way.

Version History New improved artwork and content, minor bug fixes. 1.50 Jun 15 This update refreshes the introduction section with clearer, updated illustrations and fixes a handful of small display issues. Thanks for using MasterNav! 1.49 Jun 7 Improved navigation-light graphics and animations on the vessel identification questions, plus a few display fixes and refinements. 1.48 May 31 Rule 18 rebuilt: new drag-to-reorder question format, clearer explanations with new diagrams for NUC, RAM, seaplanes and WIG craft, a dedicated breakdown of the "so far as possible" qualifier, and 27 new practice questions. 147 Apr 11 Improved learn screens throughout the app — key rules now feature improved illustrated cards with clear visual explanations. 1.46 Apr 1 Improved interface and performance enhancements for a better study experience. 1.45 Mar 17 Major update — Part D: Sound & Light Signals now fully integrated. New interactive graphics, exam questions and comprehensive coverage of sound signals, light signals and their applications.
As always, further UI refinements and performance improvements throughout 1.44 Feb 25 Major update — Part D: Sound & Light Signals now fully integrated. New interactive graphics, exam questions and comprehensive coverage of sound signals, light signals and their applications.
As always, further UI refinements and performance improvements throughout. 1.43 Feb 22 Bug fixes, and interface improvements. 1.42 Feb 17 Bug fixes, and interface improvements. 1.41 Feb 12 You can now adjust text size and brightness for easier reading. New toggle to skip confirmation prompts when skipping questions. Cleaner, smoother interface with improved spacing and responsiveness. Bug fixes - some views not displaying correctly. 1.40 Jan 26 You can now adjust text size and brightness for easier reading. New toggle to skip confirmation prompts when skipping questions. Cleaner, smoother interface with improved spacing and responsiveness. 1.39 Jan 26 Major Part C update.
Improved explanations for fishing, pilot, mine clearance, aground and anchor situations, with clearer guidance on length, aspect and exam style wording. Plus some performance, layout improvements and bug fixes. 1.38 Jan 19 Major Part C update.
Improved explanations for fishing, pilot, mine clearance, aground and anchor situations, with clearer guidance on length, aspect and exam style wording. Plus some performance and layout improvements. 1.37 Jan 2 Major Part C update.
Improved explanations for fishing, pilot, mine clearance, aground and anchor situations, with clearer guidance on length, aspect and exam style wording. Plus some performance and layout improvements. 1.36 12/16/2025 Minor fixes and improvements. 1.35 08/27/2025 Minor fixes and improvements. 1.34 07/29/2025 • The Skip button now skips individual questions instead of whole sections — more control, less hassle!
• Minor fixes. 1.33 04/14/2025 What’s New
• The Skip button now skips individual questions instead of whole sections — more control, less hassle!
• Minor fix to the COLREGs introduction: graphics now correctly show Annexes I–V instead of I–IV. 1.32 04/11/2025 Improved overall performance and stability.
Flashing light animations for Air-cushion vessels and WIG Craft now operate at the correct speed for enhanced accuracy and realism. 1.31 03/09/2025 General performance and stability improvements. 1.30 02/16/2025 -General performance and stability improvements. 1.29 06/05/2024 -General performance and stability improvements. 1.28 05/25/2024 -General performance and stability improvements. 1.27 05/25/2024 -General performance and stability improvements. 1.26 04/25/2024