Oar
For other uses, see OAR.
Traditional wooden oars
An oar is an implement used for water-borne propulsion. What distinguishes oars from paddles is that paddles are held by the paddler, and are not connected with the vessel.
Oars generally are connected to the vessel by means of rowlocks or tholes which act as a fulcrum.
Oarsmen generally face the stern of the vessel, reach as far as they can towards the stern, and insert the blade of their oar in the water. As they lean back, towards the vessel's bow, the blade of their oars sweeps the water towards the stern, providing forward thrust - see lever.
For thousands of years vessels were powered either by sails, or the mechanical work of oarsmen, or paddlers.
Some ancient vessels were propelled by either oars or sail, depending on the speed and direction of the wind (see trireme and bireme).
Construction
Oars have traditionally been made of wood. Where the oar connects to the boat there is a "collar" which stops the oar slipping past the rowlock.
The oars used in small dinghies or rafts can be less than 2 metres long. In classical times warships were propelled by very long oars that might have several oarsmen per oar.
While rowing, the oars are supported by metal frames attached to the side of the boat called outriggers. Classic oars were made out of wood, but modern oars are made from synthetic material, the most common being carbon fiber.
Oars used as trophies
The sport of competitive rowing has developed a peculiar tradition of using an oar as a memento of significant race wins.
The most common format would have the coat of arms or crest of the club or school positioned in the centre, with the crew names and the race details arranged around this.
Many older universities (Oxford and Cambridge would be prime examples) and their colleges have long histories of using the trophy oar and many examples are on display in club houses around the world.
In culture
The Norwegian municipalities of Fedje and Herøy have oars in their coat-of-arms.
Oars have been used to describe various animals with characteristics that closely-resemble the said rowing implement. The members of the Family Regalecidae, elongated deep-sea fishes, are called oarfish because their body shape is similar to that of an oar. The hawksbill turtle's genus of Eretmochelys is derived from the Latin root eretmo, which roughly translates to oar.