That make sense, but I sounds like you're pulling the plug out?!? That thing has to weigh a ton, literally! Am I reading that right? Does it pull out, the ice block, easier than it sounds? I bitch and moan about a shovel full of snow, but a block of ice that I suspect is from a big enough hole to allow two divers with all the appropriate gear to fit in!
How do you do it?
If the ice is thick, such as 18" or more, we've cut the triangle in half and used ice screws to attach rope to the blocks. Even then, with several guys and ice chisels for leverage, the blocks can still fight you a bit....
Dave C