Open Water Swimming

Swimming in natural bodies of water (lakes, oceans, rivers) rather than a pool.

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Understanding Open Water Swimming

Open water swimming (OWS) takes place in natural bodies of water — lakes, rivers, oceans, and reservoirs — rather than pools. It's the swim leg of every triathlon and a growing standalone sport with dedicated races from 1K sprints to epic channel crossings.

OWS presents challenges that pools don't: no lane lines for navigation, waves and currents, varying water temperature, limited visibility, and other swimmers in close proximity. Sighting (lifting your head to spot course buoys) is an essential skill that adds time and disrupts stroke rhythm.

The transition from pool to open water intimidates many athletes. The key is practice: swim in open water regularly before racing, learn to sight every 6–10 strokes, practice drafting behind other swimmers, and get comfortable with the sensory differences (cold water, murky visibility, waves). A wetsuit dramatically improves comfort and buoyancy.

Key Facts: Open Water Swimming

Key facts and insights about open water swimming that every endurance athlete should know.

Triathlon swim legs are always in open w

Triathlon swim legs are always in open water: 750m (sprint) to 3.8K (Ironman)

Water temperature below 76.1°F typically

Water temperature below 76.1°F typically allows wetsuit use in triathlons

Sighting adds 5–15 seconds per 100m comp

Sighting adds 5–15 seconds per 100m compared to pool swimming

Drafting behind another swimmer reduces

Drafting behind another swimmer reduces energy expenditure by 18–25%

Pro Tips: Open Water Swimming

Never swim alone in open water — always with a buddy or supervised group

Wear a bright swim cap and consider a tow float for visibility to boats

Practice sighting in the pool by swimming with eyes closed, then lifting to find a target

Acclimate to cold water gradually over several sessions before racing in it

Frequently Asked Questions About Open Water Swimming

Start shallow. Wade in, float, and swim parallel to shore where you can stand up. Bring a buddy. Wear a wetsuit for security. Do short swims and gradually increase distance over many sessions. Open water anxiety is extremely common and almost always improves with repeated, controlled exposure.

Freestyle (front crawl) is the fastest and most efficient. But there are no rules — breaststroke and backstroke are perfectly legal in triathlons. Many beginners alternate between freestyle and breaststroke. If freestyle is difficult, breaststroke is a solid option that makes sighting easy.