Most fitness trackers are not built for the ocean. They handle a shower. They survive a pool. But open water, salt, UV exposure, and actual wave impact is a completely different test — and most watches fail it quietly. These are the ones that don't.

In this guide
1. Garmin Instinct 2 Solar — Best overall 2. Apple Watch Ultra 2 — Best for Apple users 3. Garmin Fenix 8 — Best for serious athletes 4. Fitbit Sense 2 — Best budget option What to look for in a waterproof fitness tracker

1. Garmin Instinct 2 Solar — Best Overall

// our top pick
Garmin Instinct 2 Solar
Solar charging. 100m water rating. Unlimited battery life outdoors.
100m water rating Solar charging GPS + GLONASS 48hr GPS battery MIL-STD-810
The Garmin Instinct 2 Solar is the gold standard for water sports tracking. Rated to 100 meters — not splash resistant, not pool-safe, actually 100 meters — with solar charging that gives you unlimited battery life in smartwatch mode when you're outside. For SUP, ocean swimming, and beach workouts, it tracks everything: stroke count, pace, heart rate, GPS route. The interface isn't pretty but it's bulletproof.
~$299
Check price on Amazon →

2. Apple Watch Ultra 2 — Best for Apple Users

// runner up
Apple Watch Ultra 2
The most capable smartwatch on the market, built for extreme use
100m water rating EN 13319 dive certified Titanium case 36hr battery Dual-frequency GPS
If you're in the Apple ecosystem and want the best, the Ultra 2 is it. Titanium case, sapphire crystal display, EN 13319 certified for recreational diving. The ocean swim tracking, surf detection, and depth monitoring are genuinely impressive. Battery life is the only weakness — 36 hours with GPS active. For day sessions it's not a problem. For multi-day trips, the Garmin is better.
~$799
Check price on Amazon →

3. Garmin Fenix 8 — Best for Serious Athletes

// power user pick
Garmin Fenix 8
The most data-rich fitness watch on the planet
100m water rating Multi-band GPS Built-in flashlight Dive computer 29 day battery
The Fenix 8 is for people who want every metric tracked with surgical precision. Multi-band GPS that works in deep canyons and coastal cliffs. A built-in dive computer. 29-day battery life in smartwatch mode. Running dynamics, recovery time, training load, VO2 max. If you want the most complete picture of your fitness and you're serious about water sports, the Fenix 8 is the answer — but you'll pay for it.
~$899
Check price on Amazon →

4. Fitbit Sense 2 — Best Budget Option

// budget pick
Fitbit Sense 2
50m water rating, solid health tracking, fraction of the price
50m water rating 6-day battery GPS Swim tracking ECG
If you're not ready to drop $300+ on a GPS watch, the Fitbit Sense 2 is the best entry-level option for water sports. Rated to 50 meters, swim tracking works in both pool and open water, and the health monitoring is genuinely useful — ECG, stress tracking, skin temperature. GPS isn't as precise as Garmin's multi-band system but it works for most sessions. A solid starting point.
~$199
Check price on Amazon →

What to look for

Water rating is everything. 5ATM means 50 meters. 10ATM means 100 meters. For SUP and ocean swimming, 5ATM is fine. For surfing and diving, go 10ATM minimum. "Water resistant" with no ATM rating means nothing.

GPS accuracy matters on water. Standard GPS loses accuracy on open water because there are no buildings or structures to help triangulate position. Multi-band GPS like Garmin's system is significantly more accurate for paddle tracking.

Battery life is critical. A full day on the water with GPS active drains most watches fast. Look for 10+ hours of active GPS battery minimum. Solar charging is a game changer for multi-day trips.

Salt water matters. Not all watches explicitly state saltwater compatibility. Garmin and Apple Watch Ultra are both confirmed saltwater safe. For cheaper options, rinse with fresh water after every ocean session to extend life.

Our bottom line
For most people on the water, the Garmin Instinct 2 Solar is the right call. Solar charging removes battery anxiety, the 100m rating handles everything, and the $299 price is fair for what you get. Apple Watch Ultra 2 is better if you're already deep in the Apple ecosystem and want the premium experience. Budget option? Fitbit Sense 2 at $199 handles SUP and ocean swimming without issue.
RendezBlu is a participant in the Amazon Services LLC Associates Program. Some links on this page are affiliate links — if you purchase through them we may earn a small commission at no additional cost to you.