sudden death

Easy to fix.

Step 1
Cut an equal size hole in the top above the hull hole.

Step 2
Glue some polycarb or other clear plastic over the holes

viola analog fish finder 

Buy several foam in a can and spray all holes and cavities.  That will give it some positive floatation. 

If it's fiberglass you should be able to patch it, if it's a plastic boat it's toast. 

The car accident bit (and sudden death title) made reading that post confusing.  I had a mental image of a kid with his foot stuck in the kayak getting run over by a car, and was wondering why you were more worried about the kayak than the kid who apparently died suddenly... 

That would be an optical fish finder!

this would be the perfect excuse to make that yak a glass bottom yak!  you won't need a fishfinder anymore!