I had to have one!
I have an 85C30TR that I installed a small swim platform on the rear, actuallyI installed 2 on the rear. I went to the Sailors Exchange in St.Augustine whilevisiting there and I purchased 2 brand new swim platforms for a ski boat, they are about 12"X14" or 14"x18" somewhere in there and I mounted one on each sideof the ladder. I through bolted a set of stainless hinges through the back compartment and out to the hinge, I installed wood backer boards inside thecompartment. The 2 platform now swing up and tie to the rear stantions just right. I paid $20.00 ea. and another 20 or 30 for the stainless hardware.Good luck, enjoy Dean