Too late now, but it might be worth remembering that first aid for many burns, including sun-, is cooling. If you've been out in a boat, you should have access to a large supply of coolant within easy reaching distance.
In the past, I've stayed in the water until close to shivering, which I hope has helped. Certainly until the cold shower/bath.
In the past, I've stayed in the water until close to shivering, which I hope has helped. Certainly until the cold shower/bath.