This is true! If you plan on any scuba you want an open transom. Even just a sugar scoop would help, but an open transom will make your life much easier. The only problem is this means newer boat, and likely more expensive. I can imagine if you had to lug your gear over the back rail, then climb down the boarding ladder you might decide you did not really want to do it so much!Take a close look at the beneteaus, Hunters and Catalinas. I would think that a transom that allows you to enter the water easily would be high on the list of necessities considering how important SCUBA diving is to you.
MedSailor