Build Your Own Boarding Ladder (a winter project for snowy or rainy days)
Harry James, Tales
Here are some pictures of the ladder that came with "Tales". It is made out of 3/4 in plywood, I rather think AC not Marine. It is tied across top and bottom with some very thin all thread with an acorn nut on each end. It is well thought out with the hand holds and the standoff pieces at the bottom. It is very sturdy, I believe that it was probably built at the same time the interior was rebuilt - early to mid 80's. Probably hasn't received any maintenance since. It extends down below the waterline, I think it is the best boarding ladder I have had.
Dimensions are 44" by 13", the steps are dadoed in approximately 1/4 in. I would consider the All thread an essential part.