Related Clues:

• Do laps, perhaps
• Race measure
• Do the butterfly
• Gets ahead by one circuit
• One way to travel by sea
• Swimmer's routine
• Stroke, stroke, stroke...
• Sink alternative
• Runners' units
• Overtakes, in a way
• Come crawling back?
• Circuits
• Track units
• Go down a lane, maybe
• Partner of sink