Eku (エク) is a traditional Okinawan oar. It was originaly used during fights between fishermen and then included in Okinawa Kobudo.
This is a red oak oar with  a curve to one side of the paddle and a roof-like ridge along the other.
The Eku is a powerful weapon.

Eku technics are similar to Bo Technics with the difficulty of a non symmetrical weapon.

Eku is said as the favorite weapon of Shinpo Matayoshi :

Kata (カタ):

Chikin Hakachu no ekudi

Eku kata performed by  Shinpo Matayoshi :