There are three types of cave diving. These are:
Deep Cavern
A site at which the opening undercuts itself at an angle and has a maximum depth of 40 m. This type of site also includes sink holes. When you go up in deep cavern diving, you will generally come out, although you may meet with a sloped ceiling on the way.
Cave
This is a site at which you will be moving horizontally and may need to move down before you move up and out. Caves are generally shallower than caverns and sink holes and in general, you go in on 1/3 of a tank of air and come out on 1/3 of a tank of air, with 1/3 of your tank in reserve.
Penetration Diving
This type of diving goes past all limitations and is the most risky. This is where divers truly explore and go past simply recreational diving. This means going deep into caves systems with a higher potential for tight spots.