M_Boats: Question M 17

I have a new M 17 which I keep in a wet slip. It seems to keep around 2" of water in the cockpit when sitting in the slip. I don't store the motor on the boat nor do I have any stores on the boat. Of course sailing it drains. Is this typical. Also, I put the boat in the water for a short period of time to get a water mark for bottom paint again with no stores on the boat. Once the boat is loaded will that water mark change. I just want to make sure I get the bottom paint on correctly. Regards, Tony Reed