Row Boat Q & A's

What’s the difference between a canoe, a row boat, and a shell?

Why do some row boats have transoms while others do not?

How does the length of a rowboat effect its performance?

How does the beam of a rowboat effect its performance?

What effect does the bottom shape have on a row boat?

Does a row boat need a keel?

Why do some rowboats have skegs?

How does the shape of the sides effect a row boat?

What’s the difference between a canoe, a rowboat, and a shell?
A canoe is designed to be powered by hand-held paddles, usually with two people paddling, one on each side.  Canoes are narrow so the paddlers can reach over the sides without leaning over. 

A rowboat can be any boat designed to be powered by oars.  Traditional rowboats had the oarlocks mounted on the gunwales.  “Rowboat” is frequently used to mean this type of boat rather than a "shell".  Rowboats with gunwale mounted oarlocks tend to be wide to get enough spread between the oarlocks to use long oars.

A shell is designed to be powered by oars, but has the oarlocks mounted on arms (called outriggers) extending out from the sides of the boat.  This allows a greater spread between the oarlocks, allowing very long oars on very narrow boats.  Shells usually have sliding seats, which adds leg power to the stroke.

Why do some rowing boats have transoms while others do not?
The purpose of a transom in a rowing boat is to give it more beam above the water without adding extra length.  The transom on a well designed rowing boat will end above the waterline, allowing the underwater portion of the stern to come together to a trailing edge.  This will allow the water displaced to flow smoothly back together as the rowboat moves.  Other well designed rowboats are double ended having what is known as a canoe stern, such as an ordinary canoe or the beamier peapod.  A boat with a transom designed for mounting a motor is not a true rowboat, and will not row very well.

How does the length of a rowboat effect its performance?
The waterline length will effect the hull speed which is the maximum speed at which a boat can be rowed before it starts to climb its own bow wave.  The overall length, along with freeboard, sheer line, and the shape of the bow and stern determines the above water profile, which determines the windage.  Too much windage is undesirable in rowboats.

How does the beam of a row boat effect its performance?
The waterline beam effects the static (or initial) stability of a row boat.  The wider the beam the more stable the row boat.  Waterline beam also has an effect on how easily the boat moves through the water.  The narrower the waterline beam, the shorter the distance water get pushed aside as the boat moves forward, and the more easily it moves.  The beam at the gunwales effects the type of rowing system that can be used on the row boat.  Wide gunwales for oars that pivot on the gunwales, narrow gunwales for oars that pivot independently of the gunwales.

What effect does the bottom shape have on a row boat?
A flat bottom rowboat requires less draft than a v bottom.  Flat bottoms have a reputation of slapping in waves, but if the flat part of the bottom is narrow and remains under water it will not slap.  It is a common misconception that the bottom shape determines stability, but this in determined by the sides at the waterline.

Does a row boat need a keel?
Some traditionally built rowboats have a keel as a part of the construction method.  Modern building methods eliminate the need for a keel, and they are rarely seen in modern designs.  Keels or centerboards are needed on sailboats, but not on rowing boats.

Why do some rowboats have skegs?
Skegs are sometimes used in very short rowboats (dinghies) which do not have enough length to form the stern into a vertical edge.  In such a short boat, the skeg is needed to give directional stability for tracking (going straight between strokes).

How does the shape of the sides at the waterline effect a rowing boat?
This determines the dynamic (or secondary) stability of the rowing boat.  Sides that flair out above the waterline give more dynamic stability than sides that are vertical at the waterline.  Static stability is determined primarily by waterline beam.