I wouldn't stay in the water very long with it -- you aren't supposed to take baths with new tattoos, if your fingers get pruney, then your tattoo is going to get kinda fucked up and not heal very well. But if you jump in and jump right back out, you should be cool.
Also, I would for sure clean it very well right after you get out, you dont want any bacteria or anything.
I went swimming a few weeks after I got a piercing and it got all kinds of fucked up, so be careful.