yeah this is a issue being worked out at the moment...
looks like cmas have actually said yeah we're going ahead with an underwater games in Bari, Italy, in July 2007. This is supposed to include other water sports like finswimming and freediving... here's the link.
http://www.cmasbari2007.org/
however, there is a lot of work for them to do to get it up and running and opinion is divided amongst those that think about these things as to whether they can do it properly or at all.
main problem down this end of the world is the late notice and the fact that for us kiwis at least it's too soon to travel back to Europe, we're still broke from worlds!
so i guess we'll see how many countries come out of the woodwork when or if more event confirmation comes out.
liam