How about just hanging a foot off the ground with a snap shackle... hold it... be back in a second...

I just put eye splices in some parellel core line for new halyards for my 31 (cheap line, but can't see spending 2$/ft for 80 feet x 3 <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" /> ) with snap shackles.

Requires a little bit of a tug but it should work. 170lbs standing from the line. If the shackle doesn't release freely under no load (one of mine requires a little more force) then don't use it. If it opens freely then it should work.