as we used to say in the lab! They make good stuff generally. I have a Fluke 325 and an Extech clamp/DVM, haven't had trouble with either of them. I think the Fluke works better as a DVM. For higher frequency current problems I have a Fluke 199C portable scope with current probe, but that is going to be beyond what most boat owners would want to invest. It also has a 32 hour chart recorder type function, very valuable sometimes to understand certain types of problems.

One thing I have been able to do with the clamp ammeter is to track dead shorts with several branch circuits, each of which is suspect. I clamp the meter around each branch circuit in turn, set it to MAX capture, and then energize the circuit. The current spike as the fuse or breaker blows shows up as a good current spike on the meter, in the offending circuit. Might take you a few fuses to find it, but this can save hours and hours of work otherwise.

For tracing leakage currents, or simply mapping out your power usage, these instruments are irreplaceable.