I just wanted to recommend the game Endless Ocean for the Wii.
The game is basically a scuba diving sim. You go around finding fish and "interacting" with them to identify them and find out various facts about the fish. That's the main point of the game, but you also can serve as a tour guide to other divers who want to see certain fish and you have to take them to see them. You also will be asked to take pictures of certain fish for magazines. There's also a storyline where you're out searching for artifacts as well.
The thing is though, you can go out and explore whereever you want, whenever you want. It's a game where your character isn't going to be killed by anything so you can just relax and just cruise around the sea.
The graphics in the underwater portion are really amazing for a Wii game. The fish all swim around in realistic ways and just overall look great. You swim around by just pointing your Wiimote at the screen in the direction you want to go and hold down the "B" button. You can also press the "-" button once and you can swim automatically as well. It's really easy.
The game also has an online feature where you can have a friend come over to your ocean and explore around with you or you can go to their ocean and explore theirs.
If you're a fan of oceanlife or just want a nice relaxing game to play (it's also fun to just watch if someone else is playing or to play together with your kids.
I can't recommend this game enough and for $30 it's a pretty good deal.