Will an air-less pontoon float?

Question

I was just thinking about this on my way home from college. If you took a pontoon from a boat and were somehow able to vacuum all the air from inside of it, would it still float?

Answer 1

Yes, it would still float.  The amount of water displaced would not be affected in a substantial matter.  

Techincally, with the air removed, the pontoon would ride higher in the water since the weight of the air is not longer acting in a downward force.

Answer 2

The air is what provides the buoyancy - the average density of the air-filled pontoon is less than that of the water, so it floats.  Remove the air (and don't replace it with any other gas), and the pontoon will sink just as it would if it were made flat instead of tube-like.

Hope this helps!  Keep that curious mind working!  ;)