We have ip35-165 and have a 48 mile raydome on the mast just under the spreaders. I would do it again just like this on our next boat. We used the KatoMarine.com ss moint that this fixed, no moving parts. It is threaded into the mast via tapped holes. We like it there and we can see targets like marks right up to the bow, almost. The reason for there, 15 ft up is for offshore waves. One owner said to mount the dome above the waves you expect to sail into when offshore, so that sold me on up the mast as a position vs the backstay or pole mounts.
Hayden