The sheltered Portland Harbour can be dived throughout the season in most conditions other than gale force winds. Boats shuttle out and in for harbour dives allowing you to rest, de-gas and fill up in between dives.

Easy Access to Harbour Wrecks

Picking up and dropping off at Castletown Jetty just minutes away from all the harbour wrecks is Dive Beyond – operating two diving RIBS with ladders. Ideal for individuals, buddy pairs, groups and schools, Dive Beyond is based at the back of Hotel Aqua and adjacent to a Council car park which makes the trip even more convenient.

The jetty is only a short walk from the car park and centre. Better still, the premises boasts a number of additional facilities from rinsing showers to drying rooms, toilets and excellent cafe, even on-site accommodation if you want to stay local. For more information and bookings visit Dive Beyond.

Portland Harbour and Dive Sites shallower than 20m



In this section we look at dives available around Portland and inside Portland Marina with links to photos and information on the most popular harbour dives. You can also find a detailed list of all inshore and offshore dive sites with their depths at the end of this page.? If you want to shore dive instead, check out our guide to Chesil Cove.


Portland Harbour (2 to 19m) represents a semi-artificial deep water tidal basin enclosed by breakwaters. The tidal flow is limited to three areas through the breakwaters and at Ferrybridge where the harbour links to the Fleet. A number of “wrecks” lie both inside and immediately outside the breakwater walls – attracting hundreds of divers every year. These wrecks are accessible? by (club) or (commercial) dive boats with launching possible from various points including Portland Marina and a free slipway at Castletown.? All boats and vessels including kayaks & boards within the harbour require harbour permits.

The tidal range within the Harbour is small and in the order of 1.5-2.3m. The restricted water exchange leads to elevated water temperatures which accounts for the presence of several marine species beyond the typical northern limits of their range. Tidal flow within the Harbour is generally anti-clockwise, sweeping away from the Fleet, through the Port area and through the South Ship Channel. Given the depth and limited tidal range, the predominant habitat within the Harbour is one that is truly marine. There is a small area of inter-tidal habitat, particularly on the northern and western shores. In its entirety, the Harbour is an ecosystem of very high importance including a number of nationally important habitats and species.

Countess of Erne (7 to 15m). This passenger liner paddle steamer was later converted to a coal hulk but in 1935 broke loose from her moorings and sank against the breakwater inside Portland Harbour. She was built in the early 1880s and the conversion took place 1889. She is approximately 240′ long and with a 29′ beam she lies upright on the bottom making an excellent dive for novice and experienced alike. The Countess has three holds that are open on either side, a number of attractions from a large rudder to ladders and even a toilet bowl! The Red Band Fish and Lumpsuckers that visit the Countess seasonally are occasionally even joined by seals. This is definitely one dive you could do over and over again! For details and photos visit our COUNTESS OF ERNE page.

The Dredger (Breakwater wall down to 12m). The Dredger lies right outside of Portland Harbour within the shelter of Balaclava bay, right in front of the large winch and many anchors that can be spotted from see. This vessel was a sand dredger and makes an excellent dive both for training and as? a naturalist trail beside the rocks it rests against. The wreckage itself is pretty much broken up and is in two parts but offers good swim throughs and plenty of fish, squid? as well as the dozens of hermit and spider crabs. Despite its shallow depth, because it can be dived in almost any weather conditions and the lure of the wreck itself, the Dredger is even regularly visited by technical divers who use it as a platform for training. For detailed information and photographs of this wreck visit our DREDGER PAGE.

Enecuri | The Spaniard? (Harbour wall to 16m.) This 3000 ton Spanish steamship dragged her anchor in a Force 9 gale in December 1900 and was grounded on the rocks close to the Breakwater where she slipped and eventually sank. It is badly silted and fairly broken up but is full of marine life and swim-throughs with part of the vessel still intact, making it an excellent second dive of the day. It is also very accommodating to recreational and technical courses.

Landing Craft and Bombardon Unit (17-19m). Both of these wrecks lie in very close proximity and make an excellent double-wreck dive by starting off at the Landing Craft, following a line laid by local dive operators to the Bombardon Unit and returning back to entry point or surfacing on an SMB (please consult the skipper on what method is preferred for the dive). The small landing craft lies beside the Breakwater wall and is almost completely intact with its landing doors closed. It is an interesting dive that leads to the wheel house and exposed engine at the stern. (Beware there are line and cord in the engine section which should not be penetrated). From there you can either follow the line or the breakwater wall (keeping at your left) to the Bombardon Unit. This is a WWII experimental wave breaking unit apparently made for the D-Day landings and is a vessel made out of star shaped barges with lots of hatches. Be careful in poor visibility as it is easy to find oneself in the wreck without even knowing it! It makes a powerful dive in good visibility and is full of fish. For a great review and drawing of the Landing Craft and Bombardon Unit, don’t miss the article in the January 2014 issue of Diver magazine by John Liddiard and Max Ellis. SMB and Torch Highly Recommended.

Other Popular Recreational Boat Diving Sites (East and West of Portland)

Bottlebank Drift (19m). This site is right inside of the harbour close to the Hood entrance and can offer an excitingly good drift dive but in poor visibility and weather conditions, must be done with a torch. The sea bed, heavily silted, is littered with bottles, cups and plates with other oddities. At times this area is used by local and visiting dive schools to conduct recreational deep dive training where standards require a depth deeper than 18 metres. SMB Required. Torch Recommended.

James Fennel (18m). A small Admirality trawler only 123′ long that went aground on Blacknor Point in March 1920 in thick fog, slid off and sank there. The stern is complete and amidship there is an engine and boiler. This site offers some of the most enchanting sea life scenes in the area and is the spot where authors of this site first witnessed the “Dance of the Cuttlefish”, an amazing scene involving a dozen cuttlefish swaying in one place replicating the colours of each other. It is a must-do for any new visitor to Portland and a dive we regularly repeat ourselves over the season. The James Fennel also can be drifted or done as part of a drift dive. SMB Required.

Chequered Fort (18m). This is on the outside of the breakwater and just around the corner from the Fort. Depending on the tide, divers can get a good drift dive in this area. On descending, follow the wall down until you reach the gravel and sandy bottom at about 18 metres. There is some sea life amid the large rocks. SMB Required. Torch Recommended.

Black Hawk (Bow). Topedoed by a German sub in December 1944, towed into Worbarrow and beached. Declared a total loss in April 1945. The wreck was blown by explosives to clear the way for the Winfrith pipeline. It is badly broken up with large pieces of machinery present and lying in a rock shingle sea bed. There are large chains on her. SMB Required. Torch Recommended.