On-device AI · free & unlimited
Train your breath. Dive deeper.
Nereus, your AI coach, builds CO₂/O₂ tables from your personal best. A guided breath-hold timer that runs with the screen off, a worldwide dive-site directory, buddy search near you, and progress tracking down to heart rate from your Galaxy Watch or Apple Watch.
Trending dive sites
World-class freediving destinations
Handpicked from 218 dive sites across 65 countries around the globe, with optimal depth, crystalline visibility, and thriving marine life.
See it in action
Your training, beautifully in hand
A calm breath-hold timer, a program that adapts to you, and progress you can watch climb, all in one app.
Powered by AI
A coach and a plan, built around you
Tell us your goal, a target breath-hold, a depth, or just calmer breathing. Freediving Buddy designs a personalized program, adapts it as you progress, and answers your questions along the way.
- Personalized training programs that adapt to you
- A breath-hold goal with a realistic timeline
- An AI coach for technique, safety & equalization
Personalized Training
Build your training program
Design a structured multi-week training plan tuned to your personal best. Set your weekly intensity, customize CO₂ and O₂ focus days on an interactive calendar, and sync directly to the app.
- Custom CO₂ & O₂ tables calculated from your personal best
- Interactive calendar with rest and re-test milestones
- Instant deep-link sync to iOS, Android & smartwatches
Learn
A freediving course in your pocket
Bite-sized, safety-first lessons across the basics, techniques, safety, and AIDA, the same library that's in the app.
What Is Freediving?
Discover the calm, breath-hold sport of exploring the underwater world on a single breath, and what makes it so different from scuba.
CO2 vs O2 Training Tables: What Each One Actually Trains
Two staple dry-training tools, two very different jobs. Learn what CO2 and O2 tables train, how their rest patterns differ, and when to reach for each.
Never Dive Alone: The Golden Rule
The single rule that prevents most freediving fatalities. Learn why a present, trained buddy is non-negotiable for every breath-hold in the water.
Wear OS & Smartwatch
Standalone Companion AppApnea training right on your wrist
Run CO₂ and O₂ tables, track contractions, and monitor your live heart rate without ever touching your phone. Fully standalone and offline-ready.
- Standalone wrist timer with haptic vibration cues
- Live heart rate tracking (BPM) during every breath hold
- One-tap contraction logging & automatic phone sync
Get the app
Take it to the water
Freediving Buddy is launching soon on iOS and Android. Join the waitlist and we'll tell you the moment it's live.
Coming soon, join the waitlist below.