Lake Geneva, a town on Geneva Lake in Wisconsin, is the home of many houseboat residents. They roam about the lake, but have their mail delivered to individual mailboxes on docks.
The mailboat approaches each dock. At the front is the mailboat jumper jumps off, runs to the mailbox, takes the outgoing mail, puts in the incoming mail, then runs back to the boat and jumps on.
The boat doesn’t stop. It doesn’t even slow down. The jumper has to be fast and precise if he doesn’t want to get left behind.