vane, blade - flat surface that rotates and pushes against air or water

implement - instrumentation (a piece of equipment or tool) used to effect an end

boat paddle, paddle - a short light oar used without an oarlock to propel a canoe or small boat

scull - one of a pair of short-handled oars

scull - a long-handled oar mounted at the stern of a boat and moved left and right to propel the boat forward

sweep oar, sweep - a long oar used in an open boat