[Byron]

I see three guys in your attachment but no way do I recognise there the American swimmer in a skimpy blue TYR I posted on #41.

However, to say Greek is most likely to be correct as one of the water polo players has a word which could be "GREECE" on his suit and the cap has a Parthenon symbol
(that which famously stands on the Acropolis in Athens).
They wear blue suits and the side seam stripes very obviously show the Arena logo.
Having disposed of that I can now say I have progressed a little with some
research on the guy in the blue TYR* with yellow cap.
His club logo is a strange M and that is for the Mission Viejo Natadores - a prominent US club situated some 430 miles south of you and whose members
have been regularly selected for US Olympic Teams.

*be it genuine or photoshopped - and tightjeans is probably right for the latter as such a short sideseam is unusual for TYR products.