Camera-powered swim coaching

Built for performance.
Designed for safety.

The Marlin helps swimmers and coaches analyse stroke mechanics, breathing, and training progress — no wearables required. Every session also helps fund water-safety access in communities where it is needed most.

Open Web App Our Mission

95% of proceeds go directly toward water-safety programs.

Features

Everything a serious swimmer needs.

Automatic detection. No wearables. No buttons. Just mount your phone and swim.

Automatic lap detection
Mount your phone at the pool wall. The camera detects each touch and push-off — no tapping required.
Stroke counting + analysis
Counts strokes across all four competitive strokes using on-device pose estimation. Tracks cadence and underwater time per lap.
Smart rest timers
Interval, fixed-rest, or unlimited modes. Tells you exactly when to push off — configurable per set.
AI coaching insights
Per-session and trend analysis. Tells you why your speed dropped, not just that it did. Built around perception that leads to better practice.
How it works

Set up in 30 seconds.

One phone, one pool, and you're ready.

1
Mount your phone
For now, the phone just needs to be propped up somehow — any ledge or water-bottle holder works. We're building an open-source bottle mount and looking for funding and early users to make it shareable and far more accurate.
2
Pick a session
Choose from preset workouts or build your own with custom distances, sets, and rest modes.
3
Swim
The app tracks laps, counts strokes, and tells you when to push off. You focus on swimming.
The Marlin Access Program

Every session helps
fund a safer world.

When you train with The Marlin, you're not just improving your swimming — you're expanding access to water safety for people who need it most.

95% of proceeds go directly to the mission.

We run lean. Five percent covers model development and infrastructure. The rest is reinvested into aquatic facility access and water-safety education in developing countries.

95% → water-safety mission 5% → development

We are working toward a model where every paid user sponsors one free lesson and a safety certificate for a student in an underserved community. We lack full funding today — but this is the journey we are on.

🇬🇶
"He had only learned to swim eight months earlier — in a hotel swimming pool, the only place he could access. There was no Olympic-sized pool in his entire country."

Eric Moussambani of Equatorial Guinea competed in the 2000 Sydney Olympics 100m freestyle having never trained in a proper facility. His 1:52 finish became one of the most memorable moments in Olympic history — not for the time, but for what it represented: the cost of unequal access. Talent is not the barrier. Access is.

🏊
Aquatic facility access
Partnering with aquatic centres and organisations to increase access in countries where public pools are scarce or nonexistent.
🎓
Free lessons + certificates
For every user, our goal is to provide one free water-safety lesson and safety certificate to a student who otherwise couldn't afford it.
🌊
Drowning prevention
Supporting water-safety education programs globally, with a focus on children under five and communities in low- and middle-income countries.
iOS App

Coming to the App Store.

Be first to know when The Marlin launches on iOS.

You're on the list.

One email when it launches. That's it.