Modification of transom

We would like a step thru gate thru the transom to get aboard. Anyone having information on structural design limitations, I would appreciate hearing from you.

I'm afraid I don't really have an exact picture of your boat's transom in my mind, specifically how deep the cut will be, but in general I think the operation might involve a horizontal stiffening member below the gate. I'm thinking of something on the order of a 4" or 6" x 6" horizontal "ledge" member fiberglassed right below the opening. I think that the remaining upper-transom around the gate will be sufficient to distribute forces to the sides and deck without much if any extra reinforcement.

There are many design factors to take into consideration for a transom door. The following web page contains pictures of a 27' boat that I built that has transom door. http://www.parasailboat.com If this design is of interest to you I will be glad to offer assistance for your project.