Water and electronics do not make happy bedfellows. Your iPad is not designed to be water resistant. While it may survive being splashed with water if immediately dried, it will almost certainly suffer irreparable damage if allowed get wet or is submerged.
Presumably your iPad indicates that it must be restored:
If you see the Restore screen on your iPhone, iPad, or iPod touch - Apple Support
Ordinarily - if your iPad had not suffered water damage - you would be able to restore an iPad from a backup, or to Factory Settings:
Restore your iPhone, iPad or iPod touch from a backup – Apple Support
Restore your iPhone, iPad or iPod to factory settings – Apple Support
Restore all content to iPad from a backup - Apple Support
As your iPad has suffered damage, you would be best advised to take your iPad along to the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to assess your iPad. If repair isn’t possible, the iPad can be responsibly recycled - and you’ll be in the best possible place to explore possible replacement:
Genius Bar Reservation and Apple Support Options - Apple