Anybody using marine trip resettable circuit breakers

Heres another question when sizing fuses or circuit breakers. If you are lets say using halogens on a relay circuit w 12 gage wire, that are 70W high beam per lamp × 2 lamps in the circuit, and you divide the 140W total by input voltage @ 13.5V , that should give you 10.37 Amp draw under normal conditions. So wouldent a 15A fuse, or circuit breaker be sufficient for this circuit?

If low beams were lets say 55W x 2 lamps divided by 13.5V = 8.15A , then wouldent a 10A or 15A fuse or breaker be sufficient in this circuit as well.

If these amp draw numbers above are for normal operation of the hypothetical wattage in the circuits i just described figuring in amps going up a bit with heat soak from the engine compartment then wouldent the fuse or breaker amperage numbers i listed be sufficient for normal operation without any issues?

The point of the fuse or breaker is to blow quickly before a dead ahort in the wiring over amps to the point that the covering is melting. Too high of a fuse or breaker and damage to the wiring starts before it pops.

Matt