The ship I sailed in didn't have chains. The leadsman stood on a firm deck just aft of the curve of the bows.

We had one smart ass Bos'ns mate who was heaving the lead, and he thought it was silly because we had depth sounders to do that. He kept heaving the lead and calling out, by the mark 7...by the deep 6 etc. but it got to him and he yelled, "NO bottom at the pink rag" The Officer of the deck yelled, "There's no pink rag on a lead line"!
Bosn's mate yelled back, "There's no F*****g bottom either"!