Related Clues:

• Indispensable condition
• Regatta ripple maker
• Blade on a boat
• Gondola guider
• It's stroked by a rower
• Rower's implement
• It's used to row, row, row your boat
• Word with curve or wave
• Right-triangle ratio
• Stick in a scull
• Crew member's handful
• Mover for a boat without a motor
• Bireme or trireme tool
• Something thrown over the side of a boat
• Math wave