The 4m block house is located on the east wall of the quarry and is best reached by doing a perimeter dive. Entering from either the Bus Stop or closer to its location the Slipway, follow the wall on your left shoulder at a depth of 5 metres. It is 15 – 20 minute slow swim.

History & Description: The 4-metre blockhouse is a small building with a single door on the south side and 2 small square windows on the north and west sides. At a depth of 4 metres, it sits on a ledge built close to the side of the quarry wall which drops away to 20 metres below the west-facing side of the building.

The block house can be found by taking a bearing 130 degrees from the Wessex Helicopter.

Or take a bearing of 120 degrees from the bus stop (A).