This is a large harbour on the south Dorset coast. To find the slip drive round to the east side of Portland, to Castletown (the opposite side to Chesil cove). Here you will find the Aqua Hotel and a couple of dive shops including Underwater explorers (Halycon & DIR kit sellers). A permit is needed for diving within the Harbour which needs to be bought before launching. This can be obtained from Aqua Hotel next to the slip. They also have a compressor and can do Nitrox fills. If you get to the slip early there is free parking on the road nearby, otherwise you will have to pay at the Car park outside the hotel. Within the harbour against the walls of the breakwater are the wrecks of the Countess of Erne and the Landing Craft & Bombardon Unit. These are both suitable for ocean divers. Both of these sites can have low viz due to the silty bottom being kicked up. If Fathom and Blues have dropped trainee divers on the wrecks then the viz can be very poor.