Answer:

swim

Answer	Crossword Clue
SWIM	Compete in a Summer Olympics event
SWIM	Start a triathlon
SWIM	You might go for one at the beach

SWIM	Do laps in a pool
SWIM	Travel like a ray
SWIM	Triathlon start
SWIM	Make some waves
SWIM	Dip
SWIM	Sink's alternative
SWIM	Go up the creek without a paddle?
SWIM	Do laps

SWIM	Do the crawl
SWIM	Pool exercise
SWIM	Triathlon leg
SWIM	Travel in trunks?
SWIM	Go through channels?
SWIM	Thick of things
SWIM	60's dance