Beneath the surface lies the submarine, submerged except for a span of upper deck including a ladder. The hatch has been jammed open, and students will find it totally resistant to attempts to force it shut. Inside, the submarine is rather claustrophobic, as narrow corridors echo with the sounds of lapping water and any movement can quickly become cacophonous. With but a single point of entry, the submarine may seem easy to fortify, but with nowhere to run can quickly become a death trap. Some reconnaissance capability, at least, is offered by a functional periscope.