What lies beneath

From Spanish Armada shipwrecks to sunken U-boats and Viking vessels, Ireland's waters are a dream for divers of all abilities, writes BRIAN O'CONNELL

HMS Vanguard

HMS Vanguardwas en route to Cobh, Co Cork, with its sister ship, Iron Duke, in September 1875. They were a new type of steamship, with full sails, heavy armour plating and ram bows. Outside Codling Bank, off Co Wicklow, a heavy fog descended. With visibility poor, Iron Dukerammed Vanguard, causing the ship to sink in an hour.

Where?19km east of Bray.

DivingYou'll need a licence, as the ship is over 100 years old; divers can see where the ship was damaged, as well as its 9in guns. The mostly intact wreck is one of Ireland's best dives, especially in May or June, when underwater visibility is at its best.

Lusitania

The best-known shipwreck off the Irish coast, Lusitaniawas sunk by a German U-boat, in May 1915, resulting in huge loss of life. The sinking would prompt the US to enter the first World War and so change the course of history. The most recent diving expedition on the wreck took place this month; it was filmed by National Geographic. Some items relating to the ship's navigational instruments were recovered.

Where?18km off the Old Head of Kinsale, Co Cork, in about 90m of water.

DivingThe wreck is owned by an American millionaire, Gregg Bemis, who bought it in the 1960s and has taken several court challenges to assert his rights to dive on it. Next year, the results of the most recent dive will be aired on US television.

Muirchú

Previously named Helga II, Muirchú, took part in the shelling of Liberty Hall during the 1916 Rising. After the foundation of the Coastal and Marine Service, in 1923, the ship was renamed; it continued in service until 1947. In May that year it set sail from Cobh for Dublin. A combination of temporary repairs and worsening weather meant the vessel took in water and sank. A group of local divers who bought the wreck have recovered the steering binnacle, among other items. The binnacle is on view in James Kehoe's pub on Kilmore Quay, Co Wexford.

Where?East of the Saltee Islands, Co Wexford, in 57m of water.

DivingPermitted, but the ship is lying on its port side and is badly broken up, making it a tricky dive.

UC-42

In November 2010, UC-42was discovered during a survey for pipelines to the Kinsale gas field. It was a U-boat that may have been laying mines at the entrance to Cork harbour in 1917 and subsequently went missing. It was later discovered and depth-charged, although the exact location was not recorded and the position was lost over time. When it went down, possibly after detonating one of its own mines, 27 crew were lost.

Where?Just off Roches Point, Co Cork, sitting in 27m of water.

Diving UC-42is in good diving range and is therefore popular with divers, who are entitled to dive on the wreck so long as they respect the fact it is a war grave. The wreck is in good condition, sitting upright on the seabed. Some of the mines are still visible, and reports from dives suggest human bones can be seen. It may still be dangerous to enter, but the hull is relatively intact, despite being pierced in places.

River Boyne shipwreck

This wreck was found during dredging of the River Boyne in Drogheda in December 2006. In 2007 the Underwater Archeology Unit spent six months excavating the ship’s remains and taking it apart, plank by plank. It dated from the 1530s and had overlapping planks, in the Viking tradition. The remains of 14 barrels were found on it and later analysed. At the time it appeared to be carrying wine or herring.

Where?It is undergoing conservation, and the hope is that the public will be able to view the partly reconstructed boat in a museum in the near future.

U-58

Pipeline work in Kinsale uncovered another vessel in 2010, U-58, the first U-boat sunk by the Americans in the first World War. U-58, which had been patrolling off the south coast, was lining up to attack another ship when the USS Fanning spotted it. The U-boat dived but was depth- charged and forced to surface. All on board surrendered to the Americans; a photograph of the scene was used on propaganda for decades. As the Germans left the U-boat, they scuttled it so it wouldn't get into the hands of the US navy.

Where?In 60m of water, off the coast of Kinsale.

DivingThe wreck is not subject to licence rights and is relatively intact. It appeals mainly to technical divers, as its depth puts it out of reach of sport divers.

RMS Justicia

RMS Justiciawas owned and run by White Star Line, the British shipping company most famous for the ill-fated Titanic. It made several trips carrying US and Canadian troops between Europe and the US. On July 19th, 1918, the ship was torpedoed by a German U-boat. It survived the attack, but, while being towed to Lough Swilly, Co Donegal, it was again attacked and sunk by a U-boat. The wreck is in poor condition, but its majestic bow remains intact.

Where?70m underwater, off the coast of Malin Head.

DivingPermitted, although the depth makes it more appealing to experienced divers.

Empire Heritage

The cargo area of Empire Heritageholds army tanks that it was transporting from New York during the second World War. The ship was sunk on September 8th, 1944, by a single torpedo from a German U-boat, as was a convoy ship, Pinto, that was sent to rescue survivors. Rediscovered in 1995, tanks and trucks are still visible, scattered to the starboard side of Empire Heritage. Pintolies nearby, with only its engine block visible.

Where?Almost 30km off the coast of Malin Head, Co Donegal, in 67m of water.

DivingThis is one of Ireland's best wreck dives.

Possible Armada wreck

An excavation was carried out this summer on a potential Spanish Armada shipwreck off Co Donegal. It is one of the biggest finds in years, and all the information so far indicates it dates to the time of the Armada. After fighting in the English Channel, the Spanish ships tried to retreat the long way around; many took refuge on the west coast of Ireland. The weather battered some; others were scuttled or lost during a storm in September 1588. Part of this ship’s lower hull, rudder and keel have been found. Bricks from the galley, which would have housed ovens, were also located, as well as musket balls and a large amount of pottery.

Where?Off Rutland Island, close to Burtonport, in 4m of water.

DivingYou'll need a licence from the Department of Heritage. Because it is over 100 years old, the site is protected under the National Monuments Acts.