We're having difficulty determining the proper hitch ball height for our new to us 2015 13' Scamp. The Owner's' Manual states "Ball heights are relative." Then it goes on to recommend 18" to the top of the ball. (We're pulling with a 2008 Subaru Outback.)  Simply going with that recommendation, we'd need a hitch with a 2.5" rise. In looking at a couple of other recommended sources they  suggest a method for determining hitch ball height by measuring the height of the hitch on the towing vehicle, then leveling the towed trailer, measuring that height at the receiver, and adding or subtracting to come up with the rise or the drop. That figures out to a .75" rise in our situation. -- Going with the 2.5" rise would indicate that the Scamp will not be traveling level and the rear clearance would be reduced. Going with the .75" rise seems like it might prevent the ball from securely connecting with the receiver. What's the right way to determine our hitch ball height? (The Scamp doesn't have a whole lot of clearance so it seems like maximizing the clearance by traveling with the Scamp as level as possible makes sense. But perhaps it's safer to have the hitch ride a bit higher. We're talking about 1.75".)