I know most of us have friends who ride different types of ski's, so I thought I would pass this on.
I have PWC "ramps" on my boat dock. The ramps are designed to ride up on and secure the ski. The front of the hull is supported by the ramp and the back floats. My friend has a 2003 Kawi 4 stroke, and when he used the ramps, the ski would fill with water. If we left it floating level, it was fine. Pulled the ski out and angled the trailer, then put water in the hull. The water was coming in from the retainer area of the HIN plate on the back of the hull. This plate is held on by glue and then 2 plastic "push pins" put through the hull. No silicone or any other sealant. Filled the holes with silicone, covered the push pins with silicone as well and re-installed. Leak problem fixed