I agree wholeheartedly with Mark.
Just look at the potential liabilities.
The owner of the "crash boat" could be liable for not seeing the boat in trouble in time or taking too long to get there.
The helpers on the boat could be liable for not being able to untangle the sailor in trouble or lift them onto the "crash boat" or administer first aid or administer CPR.
The "crash boat" skipper and crew could be liable if someone were injured while righting the boat or the boat were damaged.
The PRO could be liable for not contacting the "crash boat" or boats and coordinating the rescue.
Everyone on the Race Committee boat could be held liable if they didn't see a boat in trouble quick enough and send a "crash boat".
Then there is the Regatta chairman who didn't have an emergency plan, know where the nearest hospital and its phone number was, check the qualifications of the "crash boat" skipper and crew, make sure there was first aid kits everywhere, and have a medivac standing by.
And don't forget the members of the host fleet. Even if they weren't at the regatta, a court could find the Fleet liable and they would have to pay.

You must NEVER use the terms "crash boat", "safety boat", "rescue boat" or the like and have a long and complete waiver on the NOR and make it very clear at the skipper meeting that everyone was responsible for their own safety.