h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

While this is not a well known sport it is quite fun. There are no formal leagues as of yet, the sport is growing.
Two canoes race upriver to a designated point. Once that point is reached by both canoes the jousting begins. The object is to submerse the opponent's canoe by whatever means possible without the use of tools (ie paddles). While poles were used in the initial inception they were proven too dangerous to use among friends. There is usually a judge on the riverbank to decide when a canoe is submersed. While the judge is not always necessary, there have been some difficult calls.
Scheduling of this event is usually difficult unless the participants have been drinking for the better part of the morning or afternoon.