Sea Caves

Sea caves appear in Careless in Red. When the tide is out, you can walk around in the cave. When the tide comes in, the caves are flooded. In this case, the water gets so deep a person trapped in the cave will drown. Sea caves have been used forever as places to hide things. They are favored by pirates.

There are sea caves along the shore of the North Sea on Hypatia. Who would look for anything valuable in a galaxy where there is ftl space travel, artificial intelligence and teleportation devices? The Hypatia pirates do it.