About 2 tons of tools, parts and supplies!
But then we're not on vacation
Let's see what would be useful for saving a vacation:
Underwater epoxy putty (Plumbing supplier)
Electric tools, including a box of crimp terminals and proper pliers (not the two-dimensional ones, those are worse than twisting wires together). Multimeter of course. Oh, and a set of WAGO terminals.
IR Thermometer gun, so many uses (troubleshoot fridge, engine, body temperature, etc)
Tube of adhesive sealant + gun
Some butyl tape/blutack
Bits of rope of various diameters
Hose clamps
Small inverter
Battery drill
Saw
Epoxy, the type that comes in a double-chambered syringe, and some cups and stir-sticks, for fixing/glueing small stuff.
Epoxy, half a litre of resin and hardener and some glass mat for fixing larger stuff.
A spare freshwater pump to swap in.
A spare toilet pump to swap in.
Silicone grease
Sandpaper
Dinghy patch kit
Spark plug for outboard
Sewing kit
And lots more