That is the question - namely, fuses or circuit breakers. Which is best? And, if considering changing from one to another, could you replace a 10A fuse with a CB of similar rating?

THE answer will help explain fundamental differences between the two systems.
Generally, a lOA fuse is intended to carry its rated current, plus any surges which normally occur in a circuit - a good example occurring when a motor starts. A typical lOA motor could have a starting current of more than 50A and its circuit would normally be protected by a fuse of much more than lOA, thus leaving the cables vulnerable to possible overload.

A circuit breaker, on the other hand, has a time delay built into it which will allow the peak to pass without tripping or damaging the CB's own mechanisms. Our lOA motor can now have a CB much closer to lOA and still be capable of carrying the circuit current. 

Fuses
Due to their inherent simplicity, fuses are much cheaper than CBs but unfortunately offer few advantages one being that a blown fuse means you have to check the circuit, otherwise it will simply go again! A positive disadvantage is that the repeated , heating and cooling weakens it, in effect gradually reducing its rated value. Oxidation will also take its toll, and you should bear both possibilities in mind before you search for faults in the circuit.
Circuit breakers
More expensive but a long-term investment. And, because they also double as switches, some of the cost is clawed back because you would need separates switches if you'd chosen fuses. Apart from predictability and reliability, another advantage is that a tripped CB can be indentified in the dark by feel. Of the five or so general types of CB, just two are commonly used on boats, namely: Thermal CB
These use a bimetallic strip as the operating mechanism. Because it takes time for the heat to take effect, that builds in a convenient delay to accommodate any current peaks. And similarly, once tripped, the bimetallic strip must first cool down before the device can be reset - and in the process allows time for the circuit and appliance to do likewise. Thermal CBs are also self-compensating when it comes to ambient temperatures. Because the strip automatically tracks the external heating effects on the cable, it will trip without delay once the heat threshold is crossed. For example, a yacht in the Caribbean, whose circuitry is already heated by its surroundings, will already be partially on the way to tripping its CBs. It follows that a yacht operating in cool conditions will have a greater margin of tolerance.

Magnetic CB
This type of protection device uses a
solenoid working against a spring, and their operation is very fast. And, as they can be reset immediately, obviously there's no time for any circuit heat to be dissipat
ed. Coupled with the fact that they're prone to spurious tripping through shock, vibration and even the slightest overload, it's not surprising that you see less of them in use. Some magnetic CBs have thermal delays to dampen

Discimination
This is the ability of a protection system to disconnect only faulty circuits while maintaining those that are sound. Discrimination is achieved by coordinating the current ratings and time settings of the CBs (or fuses) between the battery and load. As you can see from Figure 5, there are two layers of protection in the distribution circuit (some sensitive equipment might be protected locally, (making three). The devices nearest the load have the lowest current rating and the shortest operating time, with those nearest the battery having the highest current rating and and longest operating time. If, say, a short circuit occurred at the top lamp, the fault current would be large enough to operate all the protection devices from battery to load. However, the lamp's CB (lowest current rating, shortest delay) should trip fIrst to clear the fault and leave all other healthy circuits connected.