Watch does not start back after swim
Watch got wet swimming and will not operate. Had set for water use.
Apple Watch, watchOS 4
It seems you have answered your own question. Many users will only view questions that have not yet been answered, so your responses may be limited.
As noted in this support article, for Watch OS 8 and earlier, you rotate the crown instead of pressing it.
How to use Water Lock and eject water from your Apple Watch - Apple Support