The homes around Wisconsin’s Geneva Lake receive their mail by boat, a tradition begun in 1916. While the boat travels at a steady 5 mph, a “jumper” must jump onto each dock, run to the mailbox, swap the outgoing mail with the incoming, and jump back on board before the boat has traveled out of reach.

They can accomplish all this in as little as 10 seconds — but a typical career also includes one fall into the lake.