Hi All,
I wasn't thinking exactly of a plumb bob, but of something that you'd want to embed in something else. Thanks to M. Eley, it might be something like this
patent whale hoist. These are obviously not the same thing, but if you string a line in the fin, it's going to drop point first, and the weight means that it's going to hit something reasonably hard. So, I guess the question is, can you use it to retrieve something off the bottom?
I do like all those whaling tools. It's a good thing they don't show up here, or we'd all get pretty confused.
Best,
F