well worth carrying, imo. Already have the mechanics, woodworking, and electrical tools you mentioned as well as lots of 'how to' books and manuals aboard. Have (2 very) inexpensive (Craftsman) multimeters ($10 each on sale). This is an area where I could usefully upgrade. Between the tools which came with the boat and the tools I already had from the last boat I'm pretty well covered - but there are also a few gaps worth filling so long as they are not too expensive, heavy, and bulky. It's an easy thing to do now in the off-season which is why I'm doing some of it now.

Jerry