So i make a habit when trying a new server of making a b line for a beach, making a boat and going on the nautical version of INNAWOODS and finding a small island to start on in case of greifers.
Lately on yogcraft or scrougecraft style servers where the worlds are far more vibrant and all around busy it stands out more and more that, aside from the odd volcano, oceans are just a dead squid wasteland.
I know the yogbox in the tekkit launcher has those mermen caverns and there was a mod for coral reefs, but why do you think even mojang has pretty much push the oceans aside in terms of development for more stuff?
Gotta admit, the ocean's certainly the most boring part of minecraft now.
If there was a mod which allowed for scuba gear, more efficient swimming, better sight underwater, deep sea trenches, stuff like that? I'd be a very happy minecrafter. Especially if there were some nice goodies to be found, like more jewels or more frequent nodes of rarer metals.