Do you have a picture of the boat taken square to the bow or stern, taken from a distance and showing both waterline and the top of the mast?Actually since it is 1/2 of a 36 inch level, 1.5/18 which would equal 8.3 degrees
Assuming list is 8.3 degrees, you can double check your measurements as follows:
Using the main halyard with a heavy weight on it as a plumb line, go stand on the centerline of the boat. The halyard would be 6 or more feet away from the side of the mast at the level of the side deck. It would be hanging outside the beam of the boat. The beam of the boat is 11.50 feet.
Judy B