Rowlock

A rowlock[1] (UK: /ˈrɒlək/), sometimes spur (due to the similarity in shape and size), oarlock (American English)[2] or gate, is a brace that attaches an oar to a boat.

In the sport of rowing, the rowlocks are attached to outriggers (often just called "riggers"), which project from the boat and provide greater leverage.

They additionally have a locking mechanism (properly known as "the gate") across the top of the "U" to prevent the oar from unintentionally popping out of the rowlock.

In some, largely older, strict terminologies, a rowlock is a U-shaped cut-out in the top strake of a boat (usually the wash-strake).

The most recent sport racing oarlocks have a spring loaded feature to keep the oar collar firmly against the pin at all times.