If you can find the guy (hopefully, a police report was conducted), and he was stopped in the lane of traffic, your insurance company should file a claim against his for payment on the boat under the tort theory of negligence per se. This legal theory is commonly known as the "but for" rule. The analysis is: but for this guy stopping in the lane of traffic, you would not have had to swerve and your boat would not have left the trailer and become totaled.
Stay on your insurance company to pay your claim. It has the right to subrogation against his insurance company if it chooses to pursue it.
The botXXXXX XXXXXne is that you should get paid from your insurance company or the guys insurance company.
DISCLAIMER: Answers from Experts on JustAnswer are not substitutes for the advice of an attorney. JustAnswer is a public forum and questions and responses are not private or confidential or protected by the attorney-client privilege. The Expert above is not your attorney, and the response above is not legal advice. You should not read this response to propose specific action or address specific circumstances, but only to give you a sense of general principles of law that might affect the situation you describe. Application of these general principles to particular circumstances must be done by a lawyer who has spoken with you in confidence, learned all relevant information, and explored various options. Before acting on these general principles, you should hire a lawyer licensed to practice law in the jurisdiction to which your question pertains.
The responses above are from individual Experts, not JustAnswer. The site and services are provided “as is”. To view the verified credential of an Expert, click on the “Verified” symbol in the Expert’s profile. This site is not for emergency questions which should be directed immediately by telephone or in-person to qualified professionals. Please carefully read the Terms of Service (last updated February 8, 2012).