The behavior of fuses as they are blowing is a vast topic. The most important thing is that the electrical arc that occurs as the fuse opens extinguishes within a reasonable amount of time, usually some 10's of milliseconds. For a given fuse the time will depend on the current, the voltage it is interrupting, the type of load (inductive or not) and whether the circuit is AC or DC. To protect boat wiring (not equipment) as long as the fuse is rated for more voltage than the circuit e.g. more than 12 volts, you will be O.K.
This is not to be confused with the time taken to start blowing, which is a function of fuse type and current. Fuses are broadly categorized from slow blow to ultra rapid. This another vast topic.