I basically use my checklist for off-roading... minus the air compressor.
Socket set - but I would go 3/8"
combo standard wrench set plus maybe metric for an outboard
Small battery operated drill / driver and modest set of drill bits
Combo set of driver bits
Screwdriver set or one of 6-in-1 screwdriver in good shape
Big screwdriver or small pry bar
A large adjustable wrench
Small and large channel-locks
Vise grip
Pliers
diagonal cutters
Utility knife
Wirestripper
20' of 4 conductor - 16 gauge trailer wire (for emergency patches)
various wirenuts
Black electric tape
DUCT TAPE (any color
)
Jumper Cables
various hose clamps