Really dude he'll never be riding in any such place. Get real. Don't listen to those guys. What is going to be a concern is that if you want your bike to last you will not be able to do any under water riding. However coating your bike in Vaseline will help.

But seriously, I don't have much experience on a Ti frame. The basics seem to be that they are much lighter than steel, non corrosive, but still absorb more road vibe than aluminum. If it were me I'd just go out and ride, like you suggest, very similar geometries. But why not throw an aluminum and a carbon in there while your at it just to be more edjucated.