Mermaid Class Sloops
(Note: drawing contains some parts taken from

Ship Characteristics

Dimensions Length 339 ft
Beam 44 ft
Draft 16 feet
Displacement (standard) 2,300 tons
Displacement (full load) 2,520 tons
Performance Speed (max) 24 knots
Speed (cruising) 15 knots
Endurance 7,800 nm @ 15 knots
Armament Guns 2 4 inch Mark XIX, 4 40mm L60
ASW 1 Limbo


By 1959, the Royal Navy had a number of front-line warships either in service or nearing completion that had reconstructed a maritime capability adequate for Britain's remaining responsibility. By 1964, the fleet would have three aircraft carriers, four cruisers and 20 destroyers in service. However, the pre-existing collection of smaller ships that served a general "presence" role, most of which dated from before the Second World War badly needed replacement. Accordingly, work started on the design of a new sloop that could be deployed worldwide, would have sea-keeping capabilities adequate for policing and presence work, enough combat power to be taken seriously and yet would be inexpensive enough to be affordable in largish numbers. The reuslt of this demanding specification was the Mermaid class of sloops.

These ships were based on the design of coean-going tugs and whalers. They had a large hull, in fact in tonnage terms they were larger than the Cleopatra class destroyers. This gave them adequate fuel storage and internal accomodation for a group of Royal Marines. They were armed with the venerable Mark XIX twin four inch gun mount and four single 40mm Bofors guns. They laso had a single Limbo ASW mortar aft, this being in a well whose cover formed part of the helicopter deck. Sensors were largely chosen for economy but with one significant exception, they had elaborate electronic intelligence equipment. In fact, the Mermaids actually had the best ELINT and COMINT equipment in the fleet.

The first two Mermaid class sloops were ordered in the 1959 building program with three more following in 1960, four in 1961 and three in 1962. They were invariably assigned to foreign stations, the usual pattern being for two of the class to be on Mediterranean, West Indies, Indian Ocean and Far East stations each. They proved to be very popular ships, spacious and comfortable but also offering their crews a posting away from the drabness of early 1960s Britain. It also helped that the Royal Navy started a policy of allowing married men on the crews of the sloops to take their wives with them to the foreign posting. The extra carrying capacity of the Mermaids allowed the wives to travel out on the ships with their husbands, enabling them to see what the duties on board ship actually involved. It was not uncommon for such passengers to take a full part in the life of the ship including helping out with extra pairs of hands when needed. As a result, the Mermaids were happy ships and they quickly gained a reputation for being on the scene when disaster relief aid was needed. Thus, they became familiar sights on the world news. Despite their lack of absolute combat power, the Mermaid class did sterling service in re-establishing the Royal Navy as a world-wide presence.

Class Members

Name Ordered Laid Down Launched Commissioned Fate
Mermaid 1959 1959 1961 1962 Sunk by gunfire ARA Catamarca, North of South Georgia 4/1/1982
Sedna 1959 1959 1961 1962
Kraken 1960 1960 1961 1962
Proteus 1960 1960 1962 1963
Scylla 1960 1960 1962 1963
Siren 1961 1961 1963 1964
Nereis 1961 1961 1963 1964
Chessie 1961 1961 1963 1964
Lusca 1961 1961 1963 1965
Triton 1962 1962 1964 1965
Morgawyr 1962 1962 1964 1965
Seileag 1962 1962 1964 1965
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