Hi Stressed Chan, Welcome to TSF
1) take the battery out immediately if you can. If you can't do not switch it on again until you have done the following:
2) If there are any removable panels like battery covers, take 'em off
3) If it was sea (saltwater) rinse it out thoroughly with fresh water.
4) put it into a tea towel tie it in securely with string and then swing it round & round a few times to shake out and water lurking in the innards...
5) then out it in a warm dry location and leave it there for at least 48 hours preferably for longer. Do not power it up until this time has transpired.
Now a days a brief dunking in water may not do too much damage. most electronic components are well waterproof - the greatest ganger is the battery providing voltage and electrolysis etching copper away (hence needing to get the battery out asap)
With a modicom of luck, it may well be OK.