Kevin,
In years past I remember experimenting with a loop and also with a rope ladder. In both cases, the devices actually made it more difficult -- if not impossible -- to get back onto the boat because, being flexible materials, as soon as you put your foot into the loop or onto the rope ladder rung, the whole thing curved under the hull, which radically changed your leverage.

It is very difficult to talk about all these things in mere words. Wouldn't it be great to have seminars to deal with subjects like this and have a marker board and be able to make diagrams and to experiment with things in the water on various types of boats; and to demonstrate various types of tethering techniques, how to attach restrainer foot loops; and to maybe take an old hull and experiment with flotation; and to take a mast and submerge it and show how to detect and seal leaks -- and also to experiment with different types of masthead flotation.

There are endless "what-if" scenarios that could be covered in a seminar like that. It would be fascinating! And it would be nice to find out what works and what doesn't.