It's true that the bottom rung of the ladder wants to go under the boat but this isn't a big problem. Actually, I lashed a scrap piece of ss stanchion to the bottom rung so it sinks better, and with the low freeboard of the folkboat, a five rung ladder works fine. I fasten it to a deck cleat on the quarter and can use a grip on the lower part of a lifeline stanchion to help me get aboard, keeping in mind that this is a safety ladder and not a swim ladder. BTW, Plastimo makes a very nice version of the same thing. It's in their catalog as a "Safety ladder".

For a permanent swim and boarding ladder on the old Alberg 35, I really liked the folding, telescoping models made by Mystic Marine and Tops- in-Quality. The ladder was custom sized for the boat, fitted into the lifeline gate and was held in the stowed position by a velcro tie. Expensive but very handy.

I'd provide photos of my DIY ladder, but I'm still rehab-ing from hip replacement and neither my wife nor my Surgeon will let me anywhere near the boat for another month.