You actually can mount that one to the pylon as well by flipping the boom over so the mount end will be up higher, and the curve will sit on the gunnel of the boat. There was a misunderstanding in the ordering of the pylon for my 18' (they thought I said I had a hydrodyne inboard) and I got the curved inboard boom not knowing it was not the correct one. Figured out that it mounted fine basically upside down. But that one is now at the bottom of the Mississippi, and I have the "correct" one for the 18'. Both work fine though.