At this time the 'II' was dropped from her name and she served as an anti-submarine patrol vessel as well as undertaking escort duty in the Irish Sea.

She was then under control of the Department of Agriculture and Technical Instruction (Ireland) until she was taken over by the Admiralty in March 1915 when she became officially described as His Majesty's Yacht Helga, an armed steam yacht – officially an 'Armed Auxiliary Patrol Yacht'. Such was interest in her design that Canada ordered two ships to the same specification ( HMCS Galiano and HMCS Malaspina).

She was built in Liffey Dockyard in 1908 as a fishery research and protection cruiser and was named Helga II. The prefix was introduced in December 1946 when the Irish Naval Service was established with the purchase of three corvettes from the Royal Navy replacing Muirchú. The prefix LÉ is sometimes mistakenly used with Muirchú. The wheel was recovered from the wreck by local divers and can now be seen in Kehoes Pub in Kilmore Quay. She sank off the Wexford coast after disposal in 1947. Helga was purchased by the Irish Free State in 1923 and renamed Muirchú ( Irish: Hound of the Sea). She was the former Royal Navy ship HMY Helga and was involved in shelling Liberty Hall in Dublin from the River Liffey with her pair of 12-pounder naval guns during the Easter Rising of 1916. Public Armed Ship Muirchú ( Irish: ) was a ship in the service of Irish Free State's Coastal and Marine Service (CMS). later: 2 x QF 12 pounder 12 cwt naval gun.Sold to Hammond Lane Scrap Merchants Dublin, sank on delivery voyage. United Kingdom of Great Britain and Ireland HMCS Malaspina of the same design as the Muirchu

Patrol duty steam