18 feet is likely stock to the top of the arch. Anything added would need to be measured. Each boat is going to be different depending on the 3rd party add-ons, like the height of the radar arch, pole, etc.
I have a friend with an identical boat. However, he has a radar mount that allows him to mount is Sat TV antennae. I draft about 18" less than he does.
The only way to know is to measure that specific boat.
|