Re: What repair parts would you have on board??
When I was young, bullet proof and never more than two miles form shore, I went over 900 miles down the river to the Gulf and back twice in a fourteen foot skiff and an old Scott Attwater with no tools other than a Crescent wrench to change spark plugs and a pair of pliers to pull fish hooks. Now that I am older I take along enough tools to keep the engine running. I ususally do not have a set of points (the younger generation needs to learn how the primitive means of ignition works as I have met many that have not heard of points) as a point file in the feeler guage set will get me home. A spare impeller is nice when I am more than rowing distance from a shore.
For me a set of watch guage gaskets, flax packing, and a spare quart of steam oil is appropriate to my main vessel. For y'all that are exclusive IC folk, that would translate to fuel filters, a spare quart of lubricants for the engine, tranny, and final drive no matter what configuration they take and maybe a spare guage line if you don't do the electric thing, spare fuses if you do.
Plugs for any through hull fittings is mandatory. A snapped off fitting is embarassing in the middle of deep water. They take up little room and are priceless when needed.
By carefull analysis the hand tools can be brought down to a few adjustable wrenches and a few sockets and drives, a combination screwdriver, and a couple of pliers. Put them in grease, wrapped up in wax paper in a small plastic box and you are good to go.
A few rags to wipe things off are good also. I love my old Carbon Tet extinguisher on my IC rigs as I know that it will take the moisture out of the electrical system when needed. There are other alternatives.
For the sailors out there, a spare main is priceless. The main can always get you home eventually!
For all of us, the pocket knife is indespensable. All tools should be able of having a lanyard attached as a tool in the drink is no tool at all. Socket wrenches are the most at risk, yet the drives can have a string tied to it with a wrist loop for a nominal cost!
Just some thoughts.