Looking for a fitness watch for a young teenage boy.

Am looking for a tough, rugged & good fitness smart watch that shows the time in a clock face experience, therefore a round face is preferred. This would need to be good in all environments, including water only looking at measuring fitness and no need for social media …. If the strap breaks it needs to be easily replaceable. Looking at a budget of $60 – $80 possibly negotiable. I have a good idea on pricing for these so please honest sales only. If have in Harare I can collect next week 23rd Dec.