It also has stupid-deep dish wheels, and I'm betting every hole in that the frame, seatpost, handlebars etc. are closed up on purpose.
So, is your bike that light? Does it use foam tape on carbon handlebars, have a carbon seatpost and saddle and so on?
It's a question of displacement. In other words: Volume vs. weight. If the volume is bigger than the weight, it will float. If not, it'll sink.
And no, I'm not dipping my bike in saltwater or chlorinated water to test it. I'm not even doing it in fresh water. Salt water, btw, is more buoyant than fresh water. You do the test with your own bikes.
Hell, even my handlebars wouldn't float, but then they're not carbon (Ti), and they're not covered in foam.