Navigation Tools
Navigation calculators
The quick math you reach for on the exam and at the helm — time-speed-distance, converting between true and compass headings, and figuring an ETA. Work the answer here, then practice the underlying problems in the Navigation General bank.
Time · Speed · Distance
Distance = Speed × Time. Speed in knots, time in hours, distance in nautical miles.
Compass conversion (TVMDC)
True–Virgins–Make–Dull–Companions. Correcting (Compass→True) adds easterly error; uncorrecting (True→Compass) reverses it.
ETA
Arrival time from departure, distance, and speed of advance.
Using these on the exam
The USCG exam expects you to show the method, not just an answer — know the D = S × T triangle and the TVMDC correcting/uncorrecting rule cold. These tools are for checking your work and building intuition; on test day you'll do it by hand. For chart-plot problems with set and drift, see Chart Plotting.