Why does the hull of a ship typically have large volumes of air?

Question

Why does the hull of a ship typically have large volumes of air?

Answer 1

displacement

Answer 2

A boat must displace a volume a water equal to or greater than it's own weight,

this is why a Steel Ship will float

Answer 3

Large volumes of air???

Better than large volumes of water don't you think?

I mean our entire world above the water and dirt is air...even if it was a small open boat with no deck...it is full of air, assuming it is floating. Yeah...just a big scoop of air !!!  

Other than that are you refering to captive air as in tanks for reserve bouyancy?

Certainly to float it must have bouyancy...that's a no brainer. And it also stands to reason that to possess bouyancy it has a water DISPLACEMENT greater than it's own weight...I mean, talk about simple.

I just don't get the point of your question...perhaps it needs to be clearer as to your purpose.

Answer 4

buoyancy

to "float" it must displace (or push down) against the water making it float

Answer 5

RESERVE Buoyancy and buoyant force... so the ship will float, even if one compartment or hold (for a civilian ship- more for military) floods.