Here are pictures of the swim ladder I had fabricated for my boat "Sea Gypsy" #427. It is a variation of the kind of swim ladder used on the Amel boats from France. 
The advantages of this design are that it can be deployed by a swimmer in the water, it has two steps under water for easy climbing. It can be switched from STBD to Port side when necessary. The original Amel design also allowed for this to be used as a gang plank by adding plywood panel along the length...for "Med mooring" applications.

Length     79"
Width       13"
Steps         5   (2 are under water)
Tubing dia.   1"

Jim Hampson
Sea Gypsy #427
New Bern, NC