Now I'm confused:
This is the McGlasson I-30:
Even though there's no underbody profile it's difficult to believe the underbody here is going to be anything like the MKII images posted by John - in fact I'd strongly suspect its a full keel/attached rudder..
Clearly the MKII above, and the Bahama 30 below:
It seems logical that the McGlasson 30 (top) is the 'original', the 1970 Finch the 'MKII', and the B-30 a refinement of the Finch boat as they are very similar to each other in many ways (similar hull/deck, but new foils)....