an orange buoy marks a line leading down to the deep hydrobox - a large metal structure some 5 metres tall.

on top of the box is a round entrance. the box is designed to provide a dry working environment for welding and other tasks. if the port is closed, the box can be filled with air, then divers enter the box through the gap between the floor and the sides.

look out for the massive ballast weights that keep the box firmly on the bottom of Stoney Cove.