cut — now we are four. Four fearless S-boats, too far out to sea, Sunfish bombed and scrap-heaped — we are only three. Three threadbare S-boats patrolling o'er the blue, ... Two ice-bound S-boats... ... One lonely S-boat... ... The survivors, left blank in the fatalistic rhyme, were HMS Sealion (scuttled), HMS Seawolf (broken up), and HMS Sturgeon (sold). General characteristics First group The first group of S-class submarines consisted of four boats. They were smaller and slower than later classes, and carried less armament, but could be crewed by fewer men. All four were built at Chatham Dockyard, between 1930 and 1932. During the war, they operated in home waters, particularly the English Channel, and off the Scandinavian coast. The later second and third groups of S-class submarines would have their fuel capacity expanded to allow them to operate further and overcome this limitation. The mortality rate of these early boats was particularly high. Only one, HMS Sturgeon, survived to the end of the war. Ships: Two ordered under the 1929 Construction Programme: HMS Swordfish HMS Sturgeon Two ordered under the 1930 Construction Programme: HMS Seahorse HMS Starfish Second group The second group of S-class submarines consisted of eight boats. They were larger than the preceding first group and required more men to crew, but carried a similar armament. Construction was divided between Chatham Dockyard, and the yards of Scotts, of Greenock and Cammell Laird & Co Limited, of Birkenhead. All the ships were built between 1934 and 1937. During the war, they, like the submarines of the first group, mostly operated in home waters, ranging as far afield as the Bay of Biscay and the Scandinavian coast. One, HMS Sunfish, was assigned to the Soviet Navy (named V-1) and was sunk by friendly aircraft on the transfer route from Dundee to Murmansk. A large percentage of these submarines were also lost during the war. Only two, HMS Sealion and HMS Seawolf, survived to the end of the war. Ships: Two ordered under the 1931 Construction Programme: HMS Sealion HMS Shark Two ordered under the 1932 Construction Programme: HMS Snapper HMS Salmon One ordered under the 1933 Construction Programme: HMS Seawolf Two ordered under the 1934 Construction Programme: HMS Spearfish HMS Sunfish One ordered under the 1935 Construction Programme: HMS Sterlet Third group The third and by far the most numerous group of S-class submarines consisted of 50 boats.