Coros Pace 3 broken after diving in the sea

Hi! So, recently I’ve been for a swim with my Coros Pace 3 (in the sea) and I went in a bit deep (probably like 3/4 meters). When I came out of the water the watch wasn’t working. Is this normal? What can I do about it? I’ve bought it second hand (3 months ago) but the watch is about 2 years old.