When I pulled the boat up the stern end would come out of the water and settle on the bunks, but this would pull the bow away from the front chock. For the life of me I couldn't keep it in there, so I strapped it down. It worked, but then I notice that the stern was raised off the bunks, as in the picture below.

Should I shim the bunk, or is this normal? Might be a reason that the boat has almost no weight on the hitch when loaded ... I actually need to put stands on the back of the trailer so it doesn't tip up.
Excuse the dirty bottom, boat was in for a week on an archaeological survey of Hope Island, near Deception Pass ... Puget Sound Washington.

