Good smartwatch?

I'm looking for a smartwatch (as the title suggests).

The smartwatch should be waterproof (for swimming), equipped with a heart rate sensor and have the ability to display WhatsApp messages.

The appearance should resemble a normal wristwatch. The battery life should be 2 days or more. Of course, this must also be compact with my mobile phone (Huawei P20 light).

Unfortunately, I have not found a smartwatch myself to meet all the requirements.

In addition, it would be nice if it is possible to buy the Smartwatch at Expert or MediaMarkt, because I get a discount there.

I would choose a smartwatch from Samsung. The Galaxy Watch should be the best model for you. Alternatively, there would be the Galaxy Watch Active or Gear Sport.

All have a heart rate sensor, are protected from water and suitable for swimming. All can also show notifications and you can also reply to messages such as WhatsApp.

The new models, the Galaxy Watch and the Active model, are on Mediamarkt and Expert. At Mediamarkt they are definitely exhibited.

I myself have the Gear S3, the predecessor model of the Galaxy Watch, and the battery lasts about 2.5 to 3 days with me. However, the model is not suitable for swimming, although it offers protection (IP68) from water.