Legal Question in Civil Litigation in California

Your boyfriend is going to need to find the money to hire an attorney to look at the written contract, listen to all the factual details of the accident, respond to the lawsuit and cross-complain against the renter of the boat and those at fault, deal with the woman's attorney, etc. He was extremely foolish not to have insurance. He may not have been negligent, based upon the facts you relate, so might escape liability in the end, but unless you can convince the woman's attorney that he is judgment proof, he will not be dropped from the suit and probably will not even be dropped no matter what. I doubt he has the background to represent with any degree of success himself. The woman did not accept the risk of the wake tower being broken off and will get damages against someone. The contract with the renter at best protects him from the renter but not the woman. He can sue for his own damages including loss of rental income, but does the renter have any assets that can be used to pay for the damages? The lawsuit must be answered within 30 days of service.