Hi Joey

I think were on the same page! But when the boom is fitted to the gooseneck, it should hold itself on when the mainsail is attached. There probably isn't anything else to lock the boom on.

The rotation arm is usually attached to the boom via a small sheet which is adjustable (with cleat) This way the mast will follow the boom as the main is released, or the rotator arm can be released or adjusted for different modes of sailing. So the mast is limited in rotation with this anyway.

The standing rigging should still allow the mast to be rotated, the normal hound fitting has the attach points on the front surface of the mast. So theres nothing special that I'm aware of. Flick through recent threads on this forum, you'll find some info on the mast hounds and diamond attachment points.

Regards