Tides, GPS, fog, and passage planning — the instruments, the publications, and the judgment calls that keep a boat off the rocks. No theory for its own sake.
Tidal theory, reading NOAA current tables, timing tidal gates like Deception Pass and the Race, and how to use the flood instead of fighting the ebb.
How GPS accuracy actually works, why your chartplotter shows you on the rocks, raster vs vector charts, and when not to trust the chartplotter.
Fog types, radar navigation technique, COLREGS Rule 19 safe speed, staying out of shipping lanes, and how to approach a harbor entrance you cannot see.
The three-level planning hierarchy, publications to pull, waypoints that keep you off hazards, contingency harbors, weather windows, and the float plan.