Sometimes on faster rowboats for protected waters outriggers are added to increase rowlock separation.
From the en.wikipedia.org
Used in place of a rowlock.
From the en.wikipedia.org
Differs from a paddle by being longer and gaining leverage by passing through a rowlock which acts as a fulcrum to produce forward motion.
From the en.wikipedia.org
They have no ramparts above the hull, but to port and starboard there is one rowlock every four feet, varying in total number according to the size of the boat.
From the en.wikipedia.org
More examples
Peg: a holder attached to the gunwale of a boat that holds the oar in place and acts as a fulcrum for rowing
A rowlock (UK) or oarlock (US) is a brace that attaches an oar to a boat. When a boat is rowed, the rowlock acts as a fulcrum, and, in doing so, the propulsive force that the rower exerts on the water with the oar is transferred to the boat by the thrust force exerted on the rowlock.
A brick laid on the long, narrow side with the small or "header" side exposed.
Another name for the oarlock.
A brick laid on its face edge so that the normal bedding area is visible in the wall face. Frequently spelled rolok.
Brick laid where the cnd of the brick is faced outward.
A bracket which swivels on the end of the outrigger to support the oar
Brickwork with exposed ends setting vertically.
A U-shaped hole cut in the gunwale of a small boat where the oars are placed.