Aboard the HMS Witch Hunter, the crew use the witch-seeker compass to hunt down magical items and magic users. The red crystal, a shard from a larger magical object, is drawn towards magical energy. The ring of crystal around the compass helps to magnify the effect, guiding the ship towards danger.

The ship's containment unit is used to store powerful magical crystals and weapons. The solid steel and lead construction shields the crew and the ship's instruments from magical effects, while the cage structure and chains suspend the crystals to avoid them coming loose or damaging the ship.