HID lamps are also used in lamps for underwater diving. The two dive underwater, where they kiss, following which Grace disappears. Submarine eruptions are a type of volcanic eruption that occurs underwater. This island is a destination for divers who are interested in the underwater scenery. A submarine (or sub) is a watercraft capable of independent operation underwater. This style is well suited for underwater swimming. This is a type of telephone repeater used in underwater submarine telecommunications cables. The environments are varied, including mountains, caves, oceans, forests, and underwater segments. It differs from a submersible, which has more limited underwater capability. Dungeons appear in areas that include forests, caves, mountains, swamps, underwater caverns, and buildings. The Marquette Underwater Preserve lies immediately offshore. The tsunami engulfs the vehicle into a chaotic underwater maelstrom. The physics mostly relates to gases under pressure, buoyancy, heat loss, and light underwater. Depth contour lines show the shape of underwater relief. See APS amphibious rifle for considerations involving shooting power underwater.