The Last Stitch
When sailors died at sea their bodies would, more often than not, be committed to the deep. They would be wrapped in their hammocks with cannon balls or weights placed at their feet to ensure they would sink. The hammock was then sewn up with the last stitch going through the sailor’s nose. If he did not wake up at the pain, they knew he was definitely dead.
[Sources: First hand account | Image: The Burial at Sea by Frank Brangwyn, 1890]