Did a search on this subject and came up with some pretty variable data. I'm sure that is because of trailer styles and method of carrying the mast. Bob23 says about an inch short of 9'. Several others report up to 9'8". I'm looking at an elevated home that has 9'1" clearance and wondering if my 23 would go under it. And certainly I could remove the mast from its carry position and store it under. Additionally, I could deflate the tires somewhat to get an inch or so and then inflate after it is in position.
If I remember correctly (highly unlikely) my measurement was from the ground to the highest point on the bow rail.
Bob23