The mast base on the H16 for example has a hinge on the aft section of the casting. You insert a pin to complete the hinge when you raise the mast, then remove it wen the mast is up to let it rotate freely. In this case, the rotation cup is attached to the crossbar, and the ball (or male part) of the rotation system is attached to the mast.
On the Getaway, Hobie did away with the hinge concept, and reversed the placement of the cup and ball. You simply position the mast base casting (cup) againsts the ball which is bolted through the crossbar. In order to clear the substantial size of the bolt, the cup is notched on the side (see photo).
I suspect the reason for the notch to be on the side rather than aft is to allow the mast to rotate on the forward section of the mast, and for the aft edge of the mast to clear the trampoline when the mast is lying down.
While I understand Hobie's logic for this design, it certainly makes mast raising harder for folks like me who need to rig their cat for every use. May be they can redesign the mast base to slant the aft side (in order to clear the trampoline, and locate the notch on that aft edge.
Has anyone found some creative work around for this issue?