A zepper typicall has a large balloon filled with hydrogen, holding it in the air. This makes zeppers dangerous when attacked, as they can blow up when the hydrogen is lighted. Not only will the ship and crew perish, but any sky ship nearby my be blown off course, be caught in the blast and catch fire as well. The damage when an exploded zepper crashes can be devastating.
Underneath the balloon is the hull of a boat, roughly one quarter te size of the balloon. The boat is spacious and does not need to be suitable to sail on water.
Zeppers are mainly used for transporting goods over small distances. Its main defence are clockwork fighters or gunships which are launched from its belly.