Crocodiles on the Beaches of Costa Rica

Sirenas Costa Rica

About Kati Sakura
Kati Sakura is the founder of Sirenas Costa Rica, a swimming instructor, freediver, and creator of personalised swimming, freediving, and open water training programs for children and adults in Tamarindo, Guanacaste, Costa Rica.
Every person enters the water with a different story. Some want to learn to swim for the first time. Others dream of becoming more relaxed in the ocean, improving their freediving, preparing for open-water swimming, surfing, snorkelling, spearfishing, or simply spending time in the water with family and friends. Every program begins with one simple question: "What would you like to be able to do in the water?" From that moment, training is designed around the individual rather than following a standard lesson plan.
⬇ Explore Training Programs & Water Experiences
Training Built Around Your Goal
Every student arrives with a different objective.
- One surfer wants to become calmer in larger waves and stay comfortable during hold-downs.
- A spearfisher wants to remain underwater longer while using less energy.
- An open water swimmer prepares for longer distances and more challenging conditions.
- A certified freediver refines technique, buoyancy, equalisation, or relaxation.
- A child wants to swim confidently for the first time.
- An adult wants to enjoy the ocean during family vacations.
Every lesson starts exactly where the student is today and builds the knowledge, skills, confidence, and experience needed to reach the next level safely.
Many sessions are designed for families, couples, and groups of friends, where everyone follows their own program while sharing the same experience. One person may be training for a 20-meter freedive, another preparing for open water swimming, while someone else simply wants to enjoy snorkelling or relax in the ocean wearing a life jacket. Everyone trains together while working toward completely different personal goals.
An Individual Approach
Every person's anatomy, flexibility, mobility, breathing patterns, previous experience, confidence level, physical condition, and learning style are different. The same technique does not produce the same result for everyone. Training combines practical experience with knowledge from swimming, freediving, anatomy, biomechanics, breathing physiology, psychology, ocean safety, hydrodynamics, and the natural principles that govern buoyancy, movement, pressure, balance, and energy conservation.
Rather than asking students to force progress, Kati Sakura helps them understand how their own body works in the water. When students understand why something works, progress becomes more natural, movement becomes easier, and confidence develops almost automatically.
Swimming, Pool Training & Open Water
Swimming lessons are available for children and adults of all experience levels. Pool sessions provide a controlled environment where students focus on efficient body position, breathing, floating, balance, propulsion, relaxation, endurance, and technique without waves or currents.
Open water sessions transfer those skills into real ocean conditions. Students learn about waves, currents, orientation, energy management, ocean awareness, and practical safety while remaining relaxed and efficient in changing conditions.
Whether preparing for surfing, snorkelling, triathlons, family vacations, or simply enjoying the ocean with confidence, every lesson is adapted to the student's personal objectives.
Freediving
Freediving is not only about depth. It is about learning to move through the water with less effort, understanding your body, improving breathing, and remaining relaxed in situations that once felt uncomfortable. Programs may include breathing techniques, breath-hold training, static apnea, dynamic apnea, equalisation, duck dives, buoyancy control, streamlined body position, efficient finning, underwater navigation, open water adaptation, and internationally recognised safety procedures.
Some students train entirely in the pool.
Others focus exclusively on open water.
Many combine both environments depending on their goals.
Fear of Water & Water Confidence
One of Kati Sakura's longest-running programs focuses on helping both children and adults overcome fear of water and build lasting confidence in pools and the ocean. Every situation is different. Some children arrive unable to put the back of their head into the water or even stand under a shower with water running over their face. Some adults have never placed their face underwater, avoid swimming pools, or have spent years staying away from the ocean.
Others already know how to swim but lose confidence after a traumatic experience. One open water swimmer had completed a 5-kilometre race before losing someone close in a drowning accident. Although she was physically capable of swimming, she avoided open water completely for more than three years. After only a few private sessions in a calm bay, she gradually regained confidence and returned to racing.
Another student was an experienced surfer who became anxious every time a wave held her underwater. She believed she would run out of air within seconds. Through breathing training, relaxation, and breath-hold exercises, she comfortably achieved a 2-minute 30-second static breath hold in the pool and later remained relaxed at 5 meters depth for over one minute. More importantly, she returned to surfing with a completely different level of confidence. Some students celebrate their first time putting their face underwater. Some celebrate floating without support, and some celebrate swimming across a pool. Others can dive deeper than ever before.
Progress is never measured against another person. It is measured against where each student started.
What Students Often Say
Students frequently mention two things after their lessons: patience and a sense of calm. The method is never built around pressure or forcing results.
Instead, students receive the knowledge, practical skills, and understanding that their own body needs. As breathing becomes calmer, movement becomes easier.
As technique improves, unnecessary effort disappears. As understanding grows, confidence follows naturally. Whether the goal is learning to swim, improving freediving performance, preparing for open water, becoming a more confident surfer or spearfisher, helping a child enjoy the water, or overcoming aquaphobia after years of avoiding pools and the ocean, every program follows the same philosophy:
Understand first. Build confidence second. Develop skills that stay with you for life.