Four jobs on the wrist. Nothing else.
Ignore the score out of ten. Ignore the hiking maps. Ask what the strap has to do in the water.
Pool lap count. You set the length. 25 m, 50 m, 25 yd, or a weird hotel 20. The watch adds a length when you turn. Get the length wrong and every metre is a lie. Auto rest helps if you actually stop at the wall. Kick on a board fools most wrists unless the model has a drill or kickboard mode. Garmin’s Forerunner manuals are blunt: the device is for surface swimming, and scuba will void the warranty.
Open-water GPS. The pool does not need satellites. A lake does. Start the open-water profile on deck, wait for a lock, then swim. Wrist GPS in chop is messy. A shorter loop with a clear start is kinder than a three-hour meander with the watch still searching. Dual-frequency helps. It does not invent a shoreline you did not swim.
FIT files. Coaches who live in TrainingPeaks, Final Surge, or Garmin Connect send a structured workout as a FIT file. The watch beeps the next send-off. Apple’s Workout app can hold a custom pool set you built on the phone. It does not eat a .fit from the coach’s laptop. If that file is how your squad trains, buy Garmin or COROS.
Battery. A club week is six water sessions plus sleep tracking. Apple Watch Series 11 is up to 24 hours of normal use, 38 in Low Power Mode, from Apple’s own specs. Forerunner 570 is up to 11 days in smartwatch mode. COROS PACE 4 claims 19 days of daily use and 41 hours of GPS. That gap is the whole argument for not putting a phone-watch on a 13-year-old who will forget the cable.
Watch / Best at / Weak at / Rough price
Prices checked 23 August 2026. Street numbers move. Water ratings are from official specs only.
| Watch | Best at | Weak at | Rough price |
|---|---|---|---|
| Garmin Forerunner 570 | Pool lengths, open water, FIT, 11-day battery | No full maps. 5 ATM, surface only | Garmin launch $549.99. UK shops about £430–£460 |
| Garmin Forerunner 970 | Same swim stack plus maps, 15-day battery | Running-flagship money for a club metre-counter | Garmin launch $749.99. UK street about £590–£630 |
| COROS PACE 4 | 41 GPS hours, 19 days daily, TrainingPeaks, 32 g nylon | Still a run watch that also swims. 5 ATM | About £230 / $250. Wahoo UK listed £229.99 |
| Apple Watch Series 11 | Pool and open-water workouts if you already own an iPhone | Daily charge. No FIT. Not a season of event PBs | From £369, Apple UK |
| Apple Watch Ultra 3 | 100 m ISO, dual-frequency GPS, louder water sports | 42-hour battery vs 11 days. iPhone required | From £749, Apple UK |
| Polar Pacer Pro | WR50 pool and open water if you already use Polar Flow | Wrist HR in water is weak. Polar says so. 6.5-day battery | £299 on Polar UK. Sales dip lower |
| Polar Vantage V3 | WR50, AMOLED, 10-day smartwatch, Flow swimming metrics | Same Polar-only stack. Not diving | £519 Polar UK |
| Garmin fēnix 8 | 10 ATM plus dive computer if you actually dive | Hiking-computer price for a Tuesday 4,000 m | Premium. Often double a 570. Skip unless you want maps and rocks |
Garmin Forerunner. Mid-range is the buy.
Garmin announced Forerunner 570 and 970 on 15 May 2025. Launch prices were $549.99 and $749.99. Battery claims from that newsroom note: 570 up to 11 days in smartwatch mode, 970 up to 15 days. The owner’s manuals, still current in June 2026, rate both at Swim, 5 ATM. That is pressure equal to 50 m. Surface swimming. Not scuba.
I would put a 570 on a club swimmer who also runs, or a triathlete who needs one wrist for three sports. Pool swim and open water are built in. Auto rest, stroke type, drill log, SWOLF. You can send a workout from Garmin Connect. The 970 adds maps, a torch, sapphire, titanium. Fine if you already wanted a running flagship. A waste if the only question is whether Tuesday was 3,800 m or 4,200 m.
UK shops on 23 August 2026 were asking about £430 to £460 for a 570. John Lewis had 42 mm Raspberry at £459.99. Cotswold’s RRP sat at £460 with street closer to £430. Treat Garmin’s $549.99 as the official launch figure and the pounds as shop reality that week.
The watch counts completed lengths. A 25 m set in a 50 m tank, or a 33⅓ yard US pool left on 25 m, is how families get a “6,000 m week” that never happened. Garmin’s Forerunner swim chapter says the size must be correct or distance is wrong. Believe them.
Swim 2 is gone. Do not buy it as new.
Garmin Swim 2 was the dedicated swim watch. Pool, open water, GPS, CSS test. Released 2019. Garmin Rumors recorded the US shop retiring it in May 2025. Garmin Japan still shows a product page with 販売終了, discontinued. There is no Swim 3 on the current line. Swim features moved into Forerunner and fēnix.
If you already own a Swim 2, keep using it. The hardware still counts lengths. Do not pay new-watch money for a leftover carton. And do not tell a parent it is “the 2026 swim watch.” It is last year’s specialist, retired.
COROS PACE. Battery first, then the pool.
PACE 4 launched November 2025. Official COROS UK FAQ: rated to 5 ATM, 50 metres, pool and open-water recording, showers fine. Battery on the same pages: up to 41 hours of GPS in All-Systems mode, up to 19 days of daily use. Nylon band 32 g. Silicone 40 g. Dual-frequency GPS.
COROS is still a running company that learned to swim. Pool drills and interval modes landed in firmware. You can push structured work from TrainingPeaks or Final Surge. That is the FIT job without paying Forerunner 570 money. Wahoo’s UK listing on 23 August 2026 was £229.99. US coverage of the launch sat at $249. COROS’s own UK bag page did not print a live total in our fetch. Call it about £230.
Buy PACE 4 if battery and coach files matter more than Garmin Connect muscle. Skip it if you already own a Garmin chest-strap stack you refuse to leave. PACE 3 is last year’s Pace, also 5 ATM. Fine used. Not the current buy.
Apple Watch. Brilliant phone. Mediocre club week.
Current line on 23 August 2026 is Series 11 and Ultra 3. Apple UK: Series 11 from £369, water resistant 50 m under ISO 22810:2010, pool or ocean, not scuba, not high-velocity water. Ultra 3 from £749, 100 m under the same ISO, snorkel, recreational scuba to 40 m with a third-party app, high-speed water sports. Series 11 battery: up to 24 hours normal, 38 in Low Power. Ultra 3: up to 42 hours, 72 in Low Power. Needs iPhone 11 or later with iOS 26.
Pool swim and open water swim are real Workout modes: lengths, SWOLF, custom pool sets with haptics, kickboard detection on current Ultra specs. Water Lock. Rinse after chlorine. Apple is honest that water resistance is not permanent. What it will not do is last Monday to Sunday on a 14-year-old who also wants sleep tracking. What it will not do is import a coach FIT, or store last best 200 IM in 50 m beside last best 200 IM in 25 m. Close the rings. Then type the race.
Titanium and 100 m ISO are for people who also kite, dive, or already wanted Ultra. A club metre-counter does not need a siren. Spend the extra on a meet trip, or on a Forerunner that still has charge on Friday.
Polar is still relevant if Polar Flow is already home
Polar did not leave the pool. Vantage V3 is still on polar.com with firmware into 2026. Polar UK: WR50, £519. Battery 43 hours performance training, 10 days smartwatch. Pacer Pro: WR50, £299, 30 hours performance, 6.5 days smartwatch. Polar’s water note: swimming and bathing, not diving, do not press buttons underwater. Wrist optical HR in water “doesn’t work optimally.” They say so. Use a swim strap if heart rate is the point. Pool length is 25 m, 50 m, 25 yd, or custom down to 20. Open water uses GPS. Training targets live in Polar Flow and can talk to TrainingPeaks. Stay if the house already syncs Polar. Starting from nothing, buy a 570 or a PACE 4.
fēnix 8 is a hiking computer that also has Pool Swim
Garmin’s fēnix 8 owner’s manual rates it 10 ATM and 4 ATM Dive, EN 13319, depth sensor 0 to 40 m. Pool Swim and Open Water are in the activity list. Critical Swim Speed is there. So are scuba profiles, maps, a torch, and a price that belongs next to a mountain, not a kick set.
Mention it so you do not feel cheated. If you already wanted fēnix for trails and you swim twice a week, the swim profiles are fine. If you are buying a watch to swim, stop. The 570 does the four jobs. 10 ATM does not make Tuesday faster.
I would rather you spend £230 on a COROS that still has charge on Friday than £750 on a titanium hiking computer you take off at the locker.
A watch is not a PB archive
This is the sentence families skip, then they screenshot Garmin Connect into WhatsApp in March and wonder where the 100 breast went.
The wrist stores a workout. Metres. Splits. SWOLF. Maybe heart rate if the optical sensor survived the water, which Polar already warned you about. Last best is a race time with a stroke, a distance, and a course. 25 m is not 50 m. A time trial in warm-up is not a licensed heat. Meet Mobile on the balcony is not last best either. Apps that count, apps that show heats, and a log you own are three different hires. That split is in best swimming apps. This page is only the hardware.
Finzy does not import the watch. You type the session and the time. That is the point when the ranking site never saw the gala, or when the useful line is “main set 8 × 100 on 1:40, last 100 died,” not a SWOLF of 41. Why the week belongs in one place is why swimmers should log training.
Watch: metres, GPS track, FIT send-offs, battery. Log: last best by event and course, the set you actually swam, whether you showed up. Buy the first. Type the second.
How to pick. A short checklist.
- ✓Club pool, mixed strokes, one watch for run and swim? Forerunner 570.
- ✓Coach sends TrainingPeaks or Final Surge, and you hate charging? COROS PACE 4.
- ✓Already an iPhone household, will charge every night, only need lengths? Series 11. Ultra 3 only if you also dive or already wanted Ultra.
- ✓Already in Polar Flow? Pacer Pro or Vantage V3. Do not start Polar from a blank wrist in 2026 unless you like that app.
- ✓Saw a Swim 2 in a clearance bin? Leave it. Retired hardware.
- ✓Tempted by fēnix for “better water rating”? 5 ATM is enough for a pool. 10 ATM is a hiking tax.
- ✓Need last best 100 free, 25 m and 50 m, next to the week? That is not a watch setting. Type it.
