Scott,
I'm going to answer this, even though I sail a DS1.
In all the years sailing, I've had these onboard tools.
Knife
Scissors
Adjustable pliers (the two position kind)
Screwdriver
The latter two I keep in my glove compartment and have used them occasionally for some minor adjustments on launch (tightening the CB bolts/screws)
The knife is primarily intended as a safety device, most memorable use was passing it to another dinghy before a race so they cut slice a lime. (Forgot what the lime was for).
Since upgraded that to a small Leatherman tool.
The scissors are there to cut sail repair tape, should I need it.
Materials/spares:
- Sail repair tape
- Electrical tape
- Rigging tape
- Band-aid
- Spare batteries
- Odds&Ends
The two times we took real damage during a race, things were beyond anything I could have repaired on board. The times I broke a spreader, a temporary repair with tape worked fine (on land) - the spreader broke at the fitting, so all the repair had to do is secure it against the mast.
The band-aid was needed most often (and more than once, I had to substitute electrical tape).
I've never needed on the water repairs and never had to postpone a launch to go home and get more tools. If I did longer trips (in duration or distance) and/or sailed more often in stronger winds, I might need to prepare for more eventualities.
One of the items under "odds&ends" that's been useful has been a cable tie. It figured in my emergency repair of the broken spreader.