Kristian is on the money, sport watch is kind of used as a catch all these days it seems. I’ve always taken it to mean a rugged (typically stainless steel) watch with an emphasis on legibility and most of them to be lighter on the wrist. I think it’s a “know it when you see it” kind of thing.

A lot of watches fall under that definition and they vary in style and construction. When I think classic sports watch I think Rolex Explorer, Patek Nautilus, and G shock. I think between those three you’ll get a sense for what a sports watch is.

Coming from the Kamasu I have to give it a +1, personally I found the bracelet to be less than great but strapcode sells really nice upgrades.

Theres also the Kamasu 2 which is more of a homage with circular indices. 
 

I personally rock a Vostok amphibia, you can find them at significantly low prices, and you can even find them with modded bezel and the like directly from amazon. I’m partial to the 2416/710059 model, the bezel is easily swapped with skx compatible inserts, and scuba dude isn’t your only choice if youre looking for something more understated. Despite being a downgrade specswise I find it to still be a value even at 100USD, and a Great starting point as far as divers go.

I frequently see the kamasu at or below 300, it’s one of the better choices. I’ve seen the bulova lunar chrono on sale in the same price range as well. Two killer watches right there.