Dead reckoning, set and drift, running fix, compass error — the navigation math every OOW has to execute without a calculator hiccup.

Navigation problems are the cornerstone of every deck-officer written examination worldwide. Unlike the Rules of the Road module, which tests recognition and recall, navigation problems test execution under time pressure: you are given a starting position, a series of courses and speeds, a set and drift, and asked to produce a running fix, a DR position, and an ETA to the next waypoint — all without arithmetic errors and all in a format the examiner recognizes. MMCE.app's navigation-problems module is built on the premise that speed matters as much as accuracy, because a correct answer delivered after the exam ends is a failing answer.

What the exam actually tests

Navigation-problem questions test procedural competency. Given a set of inputs (latitude, longitude, course, speed, time, current set and drift, compass reading, deviation table, variation from chart) can you produce the correct output (new position, course to steer, ETA, true bearing, fix by two LOPs) without losing a decimal somewhere? Examiners grade partial credit on working, so neat plotting and correct formulas matter even when the final numeric answer is off. Expect one long problem set (20-40 minutes) on every written paper, plus chart-work on the orals.

Which credentials test this

• USCG — Mate 500-1600 GRT, Master 500-1600 GRT, Mate Unlimited, Master Unlimited (Deck General, Navigation General, Navigation Problems modules)
• MCA — OOW Unlimited (Navigation), Chief Mate, Master Unlimited
• Transport Canada (TC) — Watchkeeping Mate, Chief Mate, Master Near Coastal and Unlimited (Navigation Safety)
• AMSA (Australia) — Deck Watchkeeper (DWK), Master <3000 GT, Master Unlimited
• DG-IN (India) — 2nd Mate FG, Chief Mate FG, Master FG (Navigation Function 1)
• Maritime NZ (MNZ) — Deck Watchkeeper
• MARINA (Philippines) — Operational- and management-level STCW assessments
• RMI — Flag endorsements layered on any of the above

Core subject-matter breakdown

• Dead reckoning (DR): projecting position from last known fix using course steered and speed, without set and drift applied
• Set and drift (current triangle): vector solution for course-made-good and speed-made-good given an estimated current, or for course-to-steer given desired track
• Running fix: taking a single LOP, running the vessel on a known course and speed, advancing the LOP by the distance run, then crossing with a second LOP at a later time to produce a fix
• ETA calculations: time-speed-distance with speed changes en route, reserve fuel considerations, port arrival windows
• Mercator sailing vs Great Circle: rhumb line courses (constant compass direction) for short legs, great circle for long transoceanic passages, composite sailing using limiting latitude
• Chart scale and measurements: natural scale, latitude-scale distances, dividers technique, accuracy limits
• Distance off by vertical sextant angle: using charted height of lighthouse or headland and observed sextant angle to compute distance, table or formula method
• Compass error (CDMVT): True-Variation-Magnetic-Deviation-Compass conversion chain, mnemonic 'Can Dead Men Vote Twice', correct sign handling for east/west errors
• Time calculations: GMT (UT), Zone Time, Chronometer Time, ship's time on passage, date-line crossings
• Fix techniques: three-bearing fix, cocked hat evaluation, cross-bearings with ranges, radar range-and-bearing fix

Common pitfalls & traps

The classic CDMVT trap: candidates remember the mnemonic but botch the sign convention, applying east deviation as if it were west and ending up with a course error of twice the deviation. Always remember 'east is least, west is best' when converting compass-to-true, and reverse when going true-to-compass. On set and drift, candidates frequently draw the current vector in the wrong direction — set is the direction the current flows toward, not from. On running fixes, the LOP must be advanced along the course steered (or course-made-good if current is significant), not simply translated. Finally, great-circle distances in nautical miles require the spherical-triangle formula, not a plane-triangle approximation.

How MMCE.app prepares you

MMCE.app's navigation-problems module contains hundreds of problems spanning every sub-area above, graded by difficulty and tagged by technique. Each problem includes a worked solution that shows the plot, the formula, and the sign conventions. The AI tutor will explain not just what the right answer was, but where in your working the error entered — invaluable for problems with four or five chained steps. The adaptive engine (IRT 3PL) tracks your accuracy on each technique separately, so a strong DR plotter with weak running-fix skills will get more running-fix drills.

Related credentials on MMCE.app

Navigation problems feed directly into the Chart Work module, the Electronic Navigation (ECDIS, radar) module, and the Celestial Navigation papers for higher credentials. MMCE.app's navigation bank supports the full Mate-to-Master progression across USCG, MCA, TC, AMSA and DG-IN tracks.