I guess you already understand this one is a can of worms. If I assume the legal situation is the same as in the UK this is my understanding/experience.
Forget the race committee. They may be able to preside over a race/regatta result but even a favourable protest decision carries no weight in a court of law. Also if the insurance certificates are inspected and a competitor allowed to race the race committee/ organising club/authority could be taking on a liability.
Get the competitors information from the race organisers. It is in their interest to not be involved in legal action. If you instruct your insurance to persue the other party they may decide it is not financially in their interest to do so and you will take the hit. Start procedings against the other party. In the UK this needs to be done through a court with admiralty juristiction. If he is insured and doesn't inform the insurance company they will wipe their hands of him and he will personally take any hit.
You will have to put your case to the court. It is little different to putting it to a protest committee but it is not just a breach of racing rules you must prove but his negligence and breach of duty of care (UK-possibly dated).
The whole process is a big PITA. I have been through it after another competitor reneged on his agreement to cover repairs. It cost the other guy three times the repair bill and after the process was told the same guy had hit several other members of his club with the same attitude to his personal responsibility to other competitors. I am sure that some people use this 'you're insured get them to pay attitude' knowing what a pain it is to go through the courts.
I understand that future insurance premiums for the at fault are affected.
The above is a brief account of my own experience. Check to see if the above is applicable in your own area.

I hope this helps give some insight into one possible course of action.

Cheshirecatman