The list can be extensive depending on how much work you are willing to do. Most of the wrenches will be metric. And can range up to 24mm. Basic tools should be screwdrivers, pliers, channel locks, vice grip, adjustable wrench, needle nose plier, wire cutter, Allen wrenches, multi-meter. You can then get into aratchet sets with various sockets and extensions, filter wrenches, hack saw and the list goes on. Probably best to start a project and anticipate the tools needed. As time progresses your tools will be accumulated to coincide with your skill set. Along with that and maybe more importantly will be spare parts. Depending on your cruising distance and availability of service, carrying spare parts is a good idea. Even if you can't do the work, being able to have the part to give to the mechanic can save considerable down time. Definitely filters and belts. Then you have fuses, spare bilge pump cartridge & sensor, navigation bulbs etc.