From what little reading I've done on salvage, it seems like the race organizations need to have the tow company's sign a contract prior to the races. It could then be a "Contract salvage" for all boats that registered for the race. This would get rid of a very important part of salvage laws, the voluntary part. Maybe it could have multiple contracts in one, differentiating between flipped boats, righted boats in need of a tow, etc... to limit cost to the owner.
But the least the organizations could do is have a contract that everyone signs when they register their boat for the race. It would need to be signed by the tow company prior to racing, then that would cover everyone from things like this. It would also rid the tow company from voluntary salvage because they would be under a contract of some sort. Then they can't take your property and the cost could be under some sort of contract also.
For there to be a valid salvage claim:
1. There must be a marine peril placing the property at risk of loss, destruction, or deterioration;
2. The salvage service must be
voluntarily rendered and not required by an existing duty or by special
contract; and
3. The salvage efforts must be successful, in whole or in part.
Just a though.
Here is a good link to salvage laws.
http://www.mikkelborg.com/files/salvage.pdf