[k7cej]

I am gratified by the scholarly discussion my original post has generated--thanks to all who have contributed. Although I appreciate the various knots that have been advised, I am unlikely to be able to consult Ashley in the middle of a rescue (even though the bible always resides on board).

I have elected to replace the large loop formed by the knot in question with a loop of Spectra/Dyneema of the proper length to reach the rail on my boat when attached to the Lifesling and MOB in the water alongside. I made a loop of 1/4" spectra single-braid with a locked brummel splice, passing the loop through the D-rings on the Lifesling and through a small diameter eye-splice in the polypropylene retrieval line, also made with a locked brummel. I think this is an elegant solution, albeit one customized for the freeboard of my boat.

I did consider the rope on rope chafe on the retrieval line, but remember that this line has a relatively low force on it in use, and even practicing the quickstop and retireval will not get that many uses. The spectra loop is well suited to hoisting the MOB with accompanying higher loads (big man, wet = 300 lbs). And I have absolute confidence in the splices, which are being used in their expected orientations, as opposed to ring-loading a large eye-splice.

Regarding liability, I have written to Chuck Hawley at West Marine, the manufacturer, as well as the president of The Sailing Foundation (who was most helpful in getting us the training materials); he is heading in from a cruise and I expect him to look at this some more in the next few weeks.