Open Water Swimming Safety Guide: Tips, Insights, and Swim Preparation
Factors to consider when going for an open water swim - from assessing conditions, your gear, and planning. Learn from our experience in leading thousands of open water swims - Alcatraz and more!
What You Need to Know in Three Lines
Open water swimming is risky—skills, gear, and conditions matter every time.
Swim with a buddy; use a swim buoy & whistle; don’t go beyond your limits
Know the location you’re swimming and that conditions can change quickly
Open Water Swimming Safety Guide
Open water swimming offers adventure and challenge but comes with inherent risks. Proper preparation and safe practices are essential for a safer and enjoyable experience. This guide provides clear safety recommendations for open water swimmers in oceans, bays, lakes, and rivers.
Are open water swims safe? It depends! Your skillset, experience, conditioning, and how you’re feeling on the day all matter. Always assess conditions before entering and while in the water, adjusting your plan as needed. It’s safer to exit too soon than to stay in too long.
If swimming with Pacific Open Water Swim Co., our guided swims are planned given the tides, timing, experience level and pace of the swimmer/s in the water. Water and weather conditions along with vessel traffic will also factor into each swim.
Pacific Open Water Swim Co. provides small group swims in the San Francisco Bay. From swimming Alcatraz, Bridge-to-Bridge, Golden Gate Bridge, marathon swims, or marathon training and qualifying swims, we are a full-service swim company.
Pre-Swim Considerations
If you’re swimming in a new location, ask a lifeguard or local experienced swimmers about safety precautions. When possible, opt for a lifeguarded beach or designated and marked swim area.
If no lifeguard is present or you’re outside a marked zone, be extra cautious and identify multiple safe entry and exit points. Understand tides and currents that may heavily influence your ability (or inability) to exit the water as planned.
Water temperature – know the water temperature and your duration thresholds. (See our handy San Francisco Bay water temperatures swimming page).
Weather conditions - wind, fog, waves/surf, thunder & lightning are all factors that determine if you should start or end a swim.
Tides & currents - If swimming in the San Francisco Bay, tides heavily impact swim plans. Know the body of water you are about to swim in as rivers have strong currents and oceans have strong surf, hidden drop-offs and riptides.
Water quality - Recent storm runoff and other factors may hamper water quality making it unsafe for swimming. Objects, flotsam and jetsam (marine debris) are often just under the surface.
Water depth - Beaches can have quick drop-offs. Likewise, water that appears to be deep may not be or have submerged objects. Feet first is always a good approach.
Water activities - From sailing regattas, canoe races, jetskis, windsurfers, kiteboarders, fishing boats, ferries, and much more - even when swimming close to shore and in a group you are in danger. Swimmers do NOT have the ‘right of way’ unless you are in a protected and marked swim area.
Marine life - Understand the in-water and surrounding wildlife - from shuffling your feet when entering the water (‘stingray shuffle’) to seals, sea lions, jellyfish, otters, sharks, and more.
Structures - docks, piers, pilings, bridges, buoys, bridge footings all impact how the water flows around them, often pulling the swimmer towards the fixed object. Give a wide clearance when swimming near fixed objects, especially in faster waters.
Exit & entry points - Survey the swim area visually and select a few entry and exit points. Underwater hazards or changing tides and conditions may alter your original exit points.
A designated swim-friendly zone in South Lake Tahoe: This restricted area, spanning 3.0 miles (5 km) between Pope Beach and Baldwin Beach (except for the marina at Camp Richardson), prohibits power and sailboats, making it a prime location for open-water swimming. Always prioritize safety and awareness before entering the water.
Open Water Swim Gear and Equipment
Swimsuit – Wear a comfortable, well-fitting suit suitable for open water.
Wetsuit (optional) – A wetsuit made for open water swimming or triathlons provides warmth and buoyancy. Choose the right wetsuit based on the water temperature and how long you intend to swim. In warmer waters, a wetsuit may cause heat exhaustion - be realistic about your cold and warm water thresholds.
Brightly colored swim cap – A high-visibility cap (neon orange, yellow, pink, etc.) helps others (boats, lifeguards, your buddy) see you. It’s vital in choppy and varying level of light conditions - dawn, dusk, to glare of the sun.
Goggles – Wear good-fitting goggles and use vision-correcting goggles if needed. Have tinted and clear options as a cloudy morning may give way to a sunny day. Having the ability to sight in open water swimming is critical.
Swim buoy/tow float & whistle – Use a brightly colored tow float attached to your waist. It boosts visibility and offers flotation if you need a brief rest (note - it is not a life-saving device!). Attach a whistle to signal trouble and get attention. A whistle is better than yelling which may not be heard over wind, or other swimmers.
Earplugs (recommended) - Wearing earplugs help keep you warm, stave off cold-water vertigo, and can help prevent hearing problems over time.
Watch – Set a time for how long you plan to swim and start your timer when entering the water. Don’t rely on trying to remember your starting time as in cold water you might just forget. Don’t swim past your intended time in the water.
Optional cold-water accessories – Consider ear plugs (to prevent disorientation), neoprene caps, gloves, and booties for extra warmth in very cold water on your own. These reduce heat loss and improve comfort.
Communication device (optional) – Some swimmers elect to carry a mobile phone in a dry bag pouch in a swim buoy in case they get in trouble or need to exit the water at an unplanned location and call for help. Others rely on smartwatches such as an Apple Watch with phone capabilities. The third option is a VHF handheld marine radio in the swim buoy - but only if you are familiar with marine radio protocols.
Safe Swimming Practices
Communicate your plan. Let others know of your swim plans - where and when you’ll be swimming and what time to expect you back.
Acclimate to cold water gradually. Building your time in cold water doesn’t happen overnight. Don’t jump in expecting a long swim—build up time over multiple swims to know your limit. Wear a watch and build your duration by 5-10 minute increments. If you let weeks go by without a swim, decrease your time and build back up.
Maintain the buddy system. Stay close enough to your partner or group to see each other. Communicate with pauses or signals. If anyone struggles, swim to an exit point together. Do not send a struggling swimmer off to exit alone so you can continue your swim.
Practice good navigation and awareness. Sight periodically to stay on course and watch for obstacles, structures, boats or other in-water activities. Wear your bright cap and tow float for visibility. Don’t venture far from shore without boat support. Remember - others (rowers, windsurfers, boaters) aren’t watching or expecting you!
Respect currents and waves. If caught in a strong current or rip on your own, don’t panic or fight it head-on. Swim perpendicular (parallel to shore) to exit, then back to safety. If exhausted, signal with an arm and whistle. In surf, time entry and exit with waves.
Avoid restricted visibility. Do not swim at night, in dense fog, or during storms—limited visibility heightens collision risks and disorientation, significantly increasing the likelihood of an accident or emergency.
Know when to stop. Pay attention to how you feel. If feelings of fatigue, confusion, or numbness set in - exit the water. Hypothermia is a real risk, even for the most experienced swimmer. End your swim early and live to swim another day. Don’t keep swimming just to hit a yardage or time goal for the week or month!
After Your Swim
Exit the water carefully. Waves, rocks, or slippery surfaces can injure—exit slowly and steadily.
Dry off. Get out of your wet gear - sit down to remove a wetsuit as your balance may be a bit off. The sooner you dry off, the sooner you’ll start warming up!
Layer up. Bring loose fitting, easy to pull-on clothing (sweats, hoodies) including a warm hat, socks, and a jacket or parka. If you have HotSnapZ (reusable warming pouches) - these can feel like a luxury item.
Shiver. It’s normal while re-warming. Have a warm drink (tea, hot chocolate) and snack ready to restore energy and warmth, especially after cold swims. Walk, talk, or sit in a heated car. Don’t drive until you’re warm and clear-headed!
Report back and recover. Tell your shore contact you’re out of the water and safe. Rest and recover, seeking medical help if dizzy, nauseous, or overly fatigued. Reflect on lessons for next time.
Disclaimer
The safety information provided in this guide by Pacific Open Water Swim Co. is for general informational purposes only and is intended solely for independent, experienced, and competent swimmers. This guide is not a substitute for professional training, supervision, coaching, or medical advice.
Open water swimming is inherently hazardous and includes, but is not limited to, the risks of drowning, hypothermia, sudden illness, wildlife encounters, vessel traffic, rapidly changing weather, and limited emergency access. By using this guide or participating in any independent swim inspired by or associated with it, you acknowledge and agree to the following:
• ASSUMPTION OF RISK: You voluntarily assume all risks associated with open water swimming, including the risk of injury, illness, loss, or death, whether foreseen or unforeseen.
• NO GUARANTEE OF SAFETY: This guide does not and cannot guarantee your safety. Conditions vary by location and day. This guide is provided “as is” without warranties or guarantees of any kind.
• LIMITED SCOPE: This guide is not exhaustive. It may omit crucial local regulations, marine conditions, or hazards specific to a particular location, season, or swimmer’s ability level. You are solely responsible for obtaining additional safety information and making informed, location-specific decisions.
• WAIVER AND RELEASE OF LIABILITY: By using this guide, you agree to release and hold harmless Pacific Open Water Swim Co., its owners, partners, employees, guides, safety staff, independent contractors, affiliates, officers, agents, insurers, and partner organizations (collectively, the “Released Parties”) from any and all claims, liabilities, demands, damages, or losses of any kind arising out of or relating to your participation in any open water swimming activity, including but not limited to claims of negligence, premises liability, or failure to warn, to the fullest extent permitted by California law.
• NO DUTY OF CARE: Pacific Open Water Swim Co. has no legal duty to supervise, rescue, or monitor your activity when you are not participating in a scheduled and staff-led swim. Your use of this guide does not create a professional relationship or duty of care.
• INDEMNIFICATION: You agree to indemnify and defend the Released Parties against any claims brought by third parties arising from your actions, use of this guide, or failure to follow safety recommendations.
• GOVERNING LAW: This disclaimer shall be governed by the laws of the State of California. Any disputes arising shall be subject to binding arbitration in Marin County, California.
During organized swims operated by Pacific Open Water Swim Co., you must follow all posted policies, safety protocols, and instructions from staff or crew. Failure to do so may result in removal from the activity without refund or further obligation.
Use common sense. Follow all local regulations and lifeguard instructions. Do not swim alone unless you are experienced and prepared.