Out of the pool, into the lake, river, or sea. Open-water swimming – also known as open water swimming – is the most primal form of swimming and one of the most exciting endurance sports of all.

In open water, there are no lanes, no walls to push off from, no lines on the bottom for orientation. Instead: pure nature. Sunrises on the water. The feeling of boundless freedom. And of course, challenges too – waves, currents, changing visibility, temperature differences.

What makes open water swimming special?

Open water swimming is fundamentally different from pool swimming. You're in control – you have to know where you're swimming. Conditions change – weather, waves, currents. You swim longer distances at a stretch – no turning every 25 or 50 meters. And you experience nature up close – fish below you, birds above you, the vast horizon before you.

The distances

Open water events are available in many distances: Beginner races: 500m - 1,500m. Standard: 2.5km - 5km. Long distance: 10km (Olympic distance). Extreme distances: Channel crossings (e.g., English Channel, 34km), circumnavigations of lakes.

This guide shows you how to get started safely and successfully in open water swimming – from the basics to your first competition.

Pool swimming and open water swimming are two different sports – even though the basic movement is the same.

orientation

In a pool: lines on the bottom, walls for orientation. In open water: none of that. You have to regularly 'sight' – lift your head and look for buoys, landmarks, or other points of reference. Without orientation, you'll swim in a zigzag pattern and cover significantly more distance.

Conditions

In the pool: Constant temperature, calm water, clear visibility. In open water: Fluctuating temperatures (8-25°C depending on the body of water and season). Waves, currents, wind. Limited visibility (turbidity, refraction). Fauna – plants, fish, sometimes jellyfish.

equipment

In the pool: Swim trunks, goggles, that's it. In open water: Wetsuit (in colder water). Swimming goggles with appropriate tint. Visible swim cap (for safety). Optionally, a swim buoy (for safety and visibility).

Technical adjustments

In the pool, you can swim with a high stroke rate and a pure focus on propulsion. In open water: a slightly higher head position (for sighting). A more powerful leg kick (stability in waves). The ability to breathe bilaterally (wind/waves coming from one side). Longer, more consistent strokes (less wall push-off = more efficiency needed).

Mental component

In a pool: A controlled environment. In open water: Unknown factors, no visible boundary beneath you, sometimes long distances to the shore. This requires mental strength and the ability to remain calm.

Safety is paramount in open water swimming – open water does not forgive carelessness.

Golden rules

Never swim alone: ​​Always swim with someone – at least a swimming partner, better yet: someone on the shore or in a boat. Be visible: Wear a bright swim cap (orange, pink, neon yellow). Use a swim buoy (a dry bag attached to you). This makes you visible to boats and rescue services. Know the water: Is swimming allowed? Is there boat traffic? What are the conditions (current, temperature)? Are there any known hazards (plants, rocks, currents)? Realistically assess your abilities: Never swim out further than you can swim back.

Swimming buoy

A swim buoy (also called a Restube or swim buoy) is highly recommended. It makes you visible to boats and rescue services. It provides buoyancy for resting if needed. It can also offer waterproof storage for valuables. Investment: 20-50 euros – potentially lifesaving.

Temperature and hypothermia

Cold water is dangerous. Water below 15°C: wetsuit recommended. Water below 10°C: only for experienced cold-water swimmers. Symptoms of hypothermia: shivering, confusion, loss of coordination. When in doubt: shorter distances, wetsuit, swim with a companion.

Currents and waves

Current: Can cause you to drift. Know the current conditions. In strong currents: Don't fight against them, but swim diagonally. Waves: Make breathing and orientation difficult. Avoid breathing towards the wave. Stay calm, adjust your technique.

Avoid panic

Panic is dangerous in open water. If you feel unsafe: Turn onto your back, breathe calmly. Grab a buoy (if available). Get your bearings, stay calm. Swim to the nearest safe place.

Swimming technique in open water differs from swimming in a pool – here are the most important adjustments.

Sighting (Orientation)

The most important open-water skill. Why: In open water, there are no lines – you have to maintain your own direction. How: Just before inhaling, lift your head forward. Look at a landmark (buoy, landmark). Lower your head again and breathe normally. Frequency: Every 6-12 strokes, depending on conditions. Tips: Don't lift your head too high (it wastes energy and lowers your hips). Combine it with your swimming motion. Identify landmarks beforehand.

Waterfront location

In open water: Keep your head slightly higher than in a pool (this makes sighting easier). Keep your hips up, though. Maintain body tension – waves and currents shouldn't throw you off balance.

arm stroke

More powerful catch: The water in open water is 'denser' (more resistance due to movement). High elbow above water: Avoids contact with waves. Longer, smooth strokes: Efficient, as there are no wall pushes.

Leg kick

Slightly more powerful than in the pool – provides stability in waves. 2-beat kick for long distances (energy-saving). 6-beat kick for short distances or fast sections.

breathing

Being able to breathe bilaterally is important when wind/waves are coming from one side. Breathe towards the 'calmer' side (away from the waves). Deep exhalation underwater reduces shortness of breath.

Mass swims

In races, you often swim in a large group. Contact is normal – don't panic. Protect your arms: Swim with a slightly wider recovery stroke. Swimming in the slipstream saves energy (behind or alongside a faster swimmer). Find open space: Sometimes a small arc is worthwhile.

The right equipment makes open water swimming safer and more enjoyable.

wetsuit

The most important piece of equipment for colder water. Advantages: thermal protection, buoyancy (you swim higher and faster), protection from UV rays and minor injuries. When needed: water temperature below 20°C (for most). Below 15°C almost mandatory. Types: swimming wetsuit (thinner, more freedom of movement than a surf wetsuit). Triathlon wetsuit (optimized for swimming). Thickness: 3-5mm (the colder the water, the thicker the wetsuit). Investment: €150-500 for a good swimming wetsuit.

Swimming goggles

Must fit well (no water ingress, no pressure points). Choose the tint: Clear: For murky water, cloudy days. Tinted (smoke, blue): For sunny conditions. Mirrored: For very bright light. Polarized: Reduces glare on the water's surface. Bring a backup pair of goggles!

Swimming cap

Bright colors: orange, pink, neon yellow – for visibility. Silicone or latex: silicone is more durable and warmer. In cold weather: wear two caps, one on top of the other.

Swimming buoy / Restube

Highly recommended for all open-water swimmers. Makes you visible. Provides buoyancy for resting. Can offer waterproof storage space. Attached to the body (hip belt), it barely interferes with swimming. Investment: 20-50 euros.

Optional equipment

Earplugs: Protect against cold water in the ear (swimmer's ear). Neoprene cap: Extra warmth for the head in cold water. Neoprene gloves/booties: For very cold water. GPS watch: For distance, pace, and navigation. Sunscreen: Water-resistant, apply liberally.

Open-water swimming requires specific training – a pool alone is not enough.

Prepare in the pool

Build your base endurance: Run longer distances without a break (500m, 1000m, 2000m+). Practice sighting: Briefly look ahead every 6-10 strokes. Breathe bilaterally: Train both sides. Increase interval length: 200m, 400m instead of just 50m and 100m.

Open water training

Get out into open water as often as possible – at least once a week during the season. First sessions: Short distances, parallel to the shore. Find and navigate to landmarks. Practice sighting. Get to know the conditions (temperature, current). Advanced: Longer distances. Different conditions (waves, wind). Swim with a group (group experience). Race simulation.

Training sessions

Pool – Endurance (3,000m): 500m warm-up. 2,000m continuous (practice sighting every 10 strokes). 500m cool-down. Pool – Intervals (2,500m): 400m warm-up. 5 x 300m with 20-second rest. 4 x 100m fast. 300m cool-down. Open Water (45-60 min): Acclimatization (5 min easy swimming). Main part: Swim a triangle or rectangle (buoys for orientation). 10-15 min easy cool-down, parallel to the shore.

Specific skills

Practicing starts: Running into the water, dolphin dives. Turning around buoys: Tight turns at markers. Swimming in a group: Swimming with others, tolerating contact. Orientation: Different conditions (sun, backlighting, waves).

Ready for your first open water race? Here's what to expect and how to prepare.

Select event

For beginners: Short distance (500m - 1,500m). Familiar waters (ideally, you've trained there). Good organization with safety precautions. Wave start instead of mass start (less crowding).

Preparation

The weeks leading up to it: Train in open water at least 2-3 times. Swim the race distance at least once in training. Familiarize yourself with the course (if possible). The day before: Check your equipment (wetsuit, goggles, cap, buoy if permitted). Plan your journey. Get a good night's sleep and eat well.

competition day

Arrival: Arrive early for registration and the course briefing. Warm-up: Swim briefly to get a feel for the water temperature. Starting position: For mass starts – the rear/outer position is best for beginners (less crowding).

The race

Start: Controlled! Don't get swept away by the pack. First 100-200m: Find your own pace, don't overdo it. Navigation: Sight regularly, aim for buoys. Middle section: Maintain a steady pace, breathe in rhythm. Last 200-300m: If you still have energy – push hard. Finish: Run out of the water, smile, enjoy!

Typical mistakes

Starting too fast leads to shortness of breath and panic. Sighting too infrequently causes you to swim detours. Panic upon contact: Stay calm, find space. Incorrect equipment: Goggles fog up, wetsuit is too tight, etc.

After the race

Warm up (especially if the water is cold). Eat and drink. Reflect: What went well, what can be improved?

This plan will prepare you for your first open water race over 1-1.5 km.

Requirements

You can swim 500m continuously in a pool. You have access to open water. You have the basic equipment (goggles, ideally a wetsuit).

Weekly effort

Weeks 1-6: 3-4 hours of swimming. Weeks 7-9: 4-5 hours of swimming. Week 10: Taper, 2-3 hours.

Phase 1: Foundation (Weeks 1-4)

Focus: Build endurance, get used to open water. Per week: 2-3 times pool (1,500-2,500m). 1 time open water (20-30 min, short distances). Pool focus: Swim longer distances continuously. Practice sighting. Bilateral breathing. Open water focus: Acclimatization. Swim short distances parallel to the shore. Practice orientation.

Phase 2: Development (Weeks 5-8)

Focus: Build distance, race-specific. Per week: 2-3x pool (2,000-3,000m). 1-2x open water (30-45 min). Pool focus: 1,000m+ continuously. Intervals (300m, 400m). Changes of pace. Open water focus: Longer distances (1+ km). Triangle/rectangle courses. Swim with others (if possible).

Phase 3: Specific (Week 9)

Focus: Race simulation. Key session: Open water – race distance (1-1.5 km) in one go. Full gear (wetsuit, goggles as in race). Timing. Pool: Reduced volume, a few fast intervals.

Phase 4: Taper (Week 10)

Focus: Getting fresh. Volume: 50-60% of previous weeks. 1-2 short pool sessions. 1 short open water session (relaxation, technique). 1-2 days before the competition: Rest or very easy swimming.

Example week (Phase 2)

Mon: Pool 2,500m (intervals: 5x300m). Wed: Pool 2,000m (technique + 1,000m continuous). Fri: Rest or easy swim 1,000m. Sat/Sun: Open water 40 min (1.2-1.5 km with breaks for orientation).

After the first 1-2 km races, the long distance beckons – here open water swimming becomes a real adventure.

The distances

Middle distance: 5 km – approximately 1-2 hours in the water. Long distance: 10 km – Olympic open water distance, 2-4 hours. Extreme: 25 km+ – challenges lasting several hours. Legendary: Channel crossings (English Channel 34 km, Bosporus, etc.).

Training for long distance

Increase volume: Swim 15-25+ km weekly. Long sessions: 3-5 km continuously in the pool, and the equivalent in open water. Train your nutrition: For swims of 2+ hours, you need to eat while swimming. Cold acclimatization: It gets cold during long open water swims. Mental strength: Hours in the water require endurance.

Nutrition for long-distance athletes

For swims longer than 90 minutes, you'll need nutrition. Options: Fast-acting carbohydrates (gels, energy bars). Liquids (in bottles or cups). From the boat or at aid stations. Frequency: Every 30-45 minutes. Practice: Test in training what you can tolerate while swimming.

Cold water swimming

A discipline in its own right – swimming in water below 15°C without a wetsuit. Requires: acclimatization (gradually getting used to the cold). Understanding of hypothermia risks. Experience and safety precautions. Not for beginners!

Solo crossings

The ultimate challenge: swimming across channels, lakes, or straits. Famous routes: English Channel (England-France, ~34 km). Catalina Channel (California, 34 km). Bosphorus (Turkey, various distances). Requires: years of preparation, support boat, official sanction, and considerable expense.

For many, open water swimming is the entry point into triathlon – or a complement to it.

Swimming in the triathlon

Triathlon begins with open water swimming: Sprint: 750m. Olympic: 1.5km. Middle distance (70.3): 1.9km. Long distance (Ironman): 3.8km. Open water skills are directly transferable: navigation, swimming with a large group, wetsuit use, and starting techniques.

Differences

In a triathlon, you have to cycle and run after the swim. This means: conserve energy: don't give it your all in the swim. Minimize your leg kick: save your legs for later. Be efficient rather than going as fast as possible. In a pure open-water race, the swim is everything – you can invest more time and energy.

Cross-training

Open water events as preparation: Pure swimming competitions before the triathlon season. Gain technique and open water swimming experience. Without the strain of cycling and running.

From open water to triathlon

If you're coming from a purely swimming background and want to try triathlon: Your swimming skills are excellent. Cycling and running will need to be developed. Brick training (multiple disciplines in succession) is new. The transitions are manageable, and your swimming strength is a major advantage.

From triathlon to open water

If you're a triathlete and want to try pure swim races: You already have open water experience. You can now enjoy swimming without worrying about the bike/run leg. You might even discover new performance limits.