I m typically a large fan of finis gear.
Waterproof swimming activity tracker.
They also track swimming stats like lap counts pace and total duration.
The tracker is waterproof and swim friendly to a depth of 50 meters.
However its heart rate monitor is not as accurate when under the waters.
This activity tracker is waterproof up to 30m so you can wear this during swimming.
Additionally all waterproof activity trackers for swimming will have an atm rating which means they are rated to withstand a certain depth.
The slim design makes it unobtrusive to swim with and out of the pool its size and profile make it another tracker that s easy.
Finis swim sense waterproof fitness tracker.
So for instance a waterproof rating of 2 atm would mean that the device can withstand a depth of 20 meters.
Zeshbit fitness tracker activity tracker pedometer ip68 waterproof bluetooth sports smart waterproof swimming with activity heart rate sleep monitor blood oxygen pressure monitor for android and ios.
There are also a few different kinds of fitness trackers.