i used the ladder that they put on the donzies its white pulls out folds down three rung. but on my 98 42 with the big step bottom and classic deck, the hull has the relief in it for the ladders they install on the tall decks. but i do not have the hatch for ladder on top. so i cut a hole in bottom under swim platform made some aluminum supports to fit up inside swim platform and then used a round access hole cover the kind that twist in place to cover hole. i have also seen one of the fold down ladders aqua something mounted under swim platform ask owner how he attached he said he used what sounded like a swell nut. all the other ladders ive seen have been mounted on top and drilled straight through which idont like because clutters up the swim platform. good luck and the old post ladder that was a option that slides into place is a joke. that was the big ***** with the boat for the wife no easy way on once in water so i had to come up with something.