I wouls suspect that the rescue hook would work on most ropes found on a boat. If no one on the forum has real life experience, contact Benchmade and ask them what they know about that application. I'm sure they'll be happy to respond.

If the response is reasonably positive, I'd go ahead and give it to him. As you mention in another post, he already owns the brand plus most guys just can't resist another gear toy. The rescue hook is unique enough that that it'll get his curiousity going and I suspect he will wear it on the boat. (He should try it on similar lines as a test so he'll have experience what to expect in a true emergency.) Even if he wears a knife or multi-tool, having the rescue hook that can be used with one hand may make the difference some day. Even if he wears a fixed blade or a one-handed folder, they may require the use of second hand to hold the roop to cut. The hook would do just that, "hook" the rope allowing for true one handed use.

BTW, happy anniversay! <img src="images/graemlins/wink.gif" alt="" />