Show us your boat
Put the boat on a trailer, and park it in your driveway, then fill it up with a garden hose like a big bathtub.
Then crawl underneath, and circle any leaky rivets with a sharpie.
Drain the water out, drill out the faulty rivets, and replace them. Stainless rivets work. Also use some 3M marine sealant and she’ll be as good as new!