My tool kit is very similar to what
robhwa carries on his boat. I also carry a 20' long piece of #10 marine grade wire, with alligator clips on both ends. Sometimes this is very handy in both diagnosing and a tempory repair to an electrical circuit. I also carry several quarts extra engine oil and a bottle of lower unit lubricant and a plastic funnel to use in adding oil to the engine. I also carry a ViseGrip chain wrench(all too often I wonder what a "vicegrip" tool would be used for?). I aso carry waterpump pliers. I do carry a full metric and SAE socket set in 3/8" drive. (which has a 3/8 to 1/4 and to 1/2 adaptors) I have two sizes (one 10" and one of 4") of cresent wrenchs, I carry open end wrenchs for each nut on the motor and in the boat. The square bit for many screws in the C Dory is called a "Robertson" bit, and I carry #1 and #2. although most are #1 in our boats. I also carry an icepick, and very small screw driver set, such as for eyeglasses set. I also have a straight punch in 1/8" and 1/4", a small ball peen hammer. If in remote areas there will also be a small axe or hatchet on the boat, but not in the tool bag. A ratchet crimping tool is both in my electrical box in the truck as well as in the boat, along with several of every type of connector used in that boat, plus ring terminals. We never use "U" shaped terminals.
I use the jump box to power my inflator for the inflatable when on the cabin top or in the water. We carry the inflatable rolled up when on the road. We also carry a rechargable Dremel tool, with multiple accessories, from sanding discs and drums, to metal cut off wheels and metal grinding bits. For long trips we also add a Ryobi electric drill with full set of bits and appropriate adaptors. We carry an electric impact wrench, plus a manual impact socket set in the tow vehicle.
I have a small clear tackle box which has multiple screws (both wood and sheet metal), machine bolts, washer and nuts of multible sizes in both metric and SAE standards. Also specifically the machine screws we use to connect ring terminals at connector strips. I also have a sailmaker needle, some heavy thread, plus a speedy awl for canvas repair. A cheap "set" for the snaps swaging along with extra male and female snaps are also in this box. In the truck is penetrating oil--usually PB blaster or AeroKroil. I carry spare lightbulbs for any incendsecant lights aboard. I change out most light fixtures to LEDs in both white and red, with an on- off-on switch which I add to the side of the case. I also carry a few spare LEDs in both white and in red.
There are extra hose clamps of allsizes. On long trips, I also carry a couple of short lenths of clear/reinforced water supply tubing, with several end to end fittings. I carry multiple zip ties in both black and colors, and in 1/8" and 1/4" sizes I am sure that there are a few specialized fitting I may have missed.
Vise Grip chain wrench below:
I do not use specific Stainless Steel tools, but rinse off with fresh water and dry any tool exposed to salt water. Then a light spray of LPS #2. I also carry dry silicone lubricant for the window tracks, and for the trailer bunks before retrieving the boat. When we had motor bikes on the deck of our larger boat, we sprayed them down with LPS #3 peroidically and especially before an ocean crossing. The bikes were lashed to the deck, standing up, with a lower cover put on before lashing, but after spraying, and over that an upper cover from the top down to the deck lashing points. That prevented any corrosion on the bikes and accessories.
