I have a 2002 blazer 210 and when it rains the boxes leak water. My boat always stays in a shed out the weather but this while fishing out of town we had a bad rain storm and my boat was parked leaning to the right on a hill and the back storage box got 4 gallons of water In it and the night before got 3” water in it (it didn’t rain as much) all the boxes leak every time it rains but it’s the first time that much got in. I can’t figure it out it has a lip and gasket and lid closes on lip. Any help will be appreciated.