E - boat E - boats ( German : " Schnellboot " , or " S - Boot " , meaning " fast boat " ) was the designation for fast attack craft of the Kriegsmarine during World War II . It is commonly held that the British used the term " E " for " Enemy " . The S - boat was a very fast vessel , able to cruise at 40 or 50 knots , and its wooden hull meant it could cross magnetic mine fields unharmed . It was better suited to the open sea and had substantially longer range ( approximately 700 nautical miles ) than the American PT boat and the British Motor Torpedo Boat ( MTB ) . As a result , the Royal Navy later developed better matched versions of MTBs using the Fairmile ' D ' hull design . History . Development . As a result of the Treaty of Versailles , Germany ' s military production was severely curtailed . However , small patrol craft were not subject to any strictures . S - boats can trace their lineage back to a private motor yacht — a 22 - ton - displacement , 34 - knot craft called " Oheka II " , which had been built by the German shipbuilding company Lürssen in 1927 for a wealthy financier and patron of the arts , Otto Kahn . This design was chosen because the theatre of operations of such boats was expected to be the North Sea , English Channel and the Western Approaches . The requirement for good performance in rough seas dictated the use of a round - bottomed displacement hull rather than the flat - bottomed planing hull that was more usual for small , high - speed boats . Lürssen overcame many of the disadvantages of such a hull and , with the " Oheka II " , produced a craft that was fast , strong and seaworthy . This attracted the interest of the German Navy , which in 1929 ordered a similar boat but fitted with two torpedo tubes . This became the " S - 1 " , and was the basis for all subsequent S - boats . After experimenting with the " S - 1 " , the Germans made several improvements to the design . Small rudders added on either side of the main rudder could be angled outboard to 30 degrees , creating at high speed what ' s known as the Lürssen Effect . This drew in an " air pocket slightly behind the three propellers , increasing their efficiency , reducing the stern wave and keeping the boat at a nearly horizontal attitude " . This was an important innovation as the horizontal attitude lifted the stern somewhat , allowing even greater speed , and the reduced stern wave made S - boats harder to see , especially at night . Operations with the Kriegsmarine . S - boats were often used to patrol the Baltic Sea and the English Channel in order to intercept shipping heading for the English ports in the south and east . As such , they were up against Royal Navy and Commonwealth ( particularly Royal Canadian Navy contingents leading up to D - Day ) , Motor Gun Boat s ( MGBs ) , Motor Torpedo Boat s ( MTBs ) , Motor Launch es , frigates and destroyer s . They were also transferred in small numbers to the Mediterranean , and the Black Sea by river and land transport . Some small S - boats were built as boats for carrying by auxiliary cruisers . Crew members could earn an award particular to their work — " Das Schnellbootkriegsabzeichen " — denoted by a badge depicting an S - boat passing through a wreath . The criteria were good conduct , distinction in action , and participating in at least twelve enemy actions . It was also awarded for particularly successful missions , displays of leadership or being killed in action . It could be awarded under special circumstances , such as when another decoration was not suitable . " Schnellboote " of the 9th flotilla were the first naval units to respond to the invasion fleet of Operation Overlord . They left Cherbourg harbour at 5 a . m . on 6 June 1944 . On finding themselves confronted by the entire invasion fleet , they fired their torpedoes at maximum range and returned to Cherbourg . During World War II , S - boats sank 101 merchant ships totalling 214 , 728 tons . In addition , they sank 12 destroyers , 11 minesweepers , eight landing ships , six MTBs , a torpedo boat , a minelayer , one submarine and a number of small merchant craft . They also damaged two cruisers , five destroyers , three landing ships , a repair ship , a naval tug and numerous merchant vessels . Sea mine s laid by the S - boats were responsible for the loss of 37 merchant ships totalling 148 , 535 tons , a destroyer , two minesweepers and four landing ships . In recognition of their service , the members of " Schnellboot " crews were awarded the Knight ' s Cross of the Iron Cross on 23 occasions , and the German Cross in Gold on 112 occasions . Italian MS boat . The poor seaworthiness of the MAS boats led the Italian Navy to build its own version of S - boats , called simply MS ( " Motoscafo Silurante " ) . The prototype was designed on the pattern of six German - built S - boats captured from the Yugoslav Navy in 1941 . Notably , two of them sank the largest warship ( the British cruiser ) that was sunk by this kind of vessel in World War II . Two MS boats were used to infiltrate a party of 14 Italian marines behind the Allied lines in Egypt on 3 September 1942 . The marines blew up a railway and an aqueduct before being captured . Thirty - six of these vessels were completed by 1943 . Service in the Spanish Navy . The " Kriegsmarine " supplied the Spanish Navy with six S - boats during the Spanish Civil War , and six more during the Second World War . Another six were built in Spain with some assistance from Lürssen . One of them , either the " Falange " or the " Requeté " , laid two mines that crippled the British destroyer HMS " Hunter " off Almería on 13 May 1937 . The German - built boats were discarded in the 1960s , while some of the Spanish - built ones served until the early 1970s . S - Boat in China . The Chinese Nationalist Navy had three S - 7 S - boats during the Second Sino - Japanese War ( World War II in China ) . One was destroyed by Japanese planes , one was lost , and one was captured by the People ' s Liberation Army during the Chinese civil war . The People ' s Liberation Army Navy used it as a patrol boat until 1963 . The Chinese Nationalist Government had also ordered eight S - 30 S - boats and a boat carrier , but they joined the Kriegsmarine in 1939 . Post - war service . Royal Navy . At the end of the war about 34 S - boats were surrendered to the British . Three boats , " S - 130 " ( renamed " P5230 " ) , " S - 208 " ( " P5208 " ) and " S - 212 " ( " P5212 " ) were retained for trials . Between 1949 and 1956 , Operation Jungle , a joint operation was established between MI6 , the CIA and the Gehlen Organization to insert agents into the Baltic states and Poland by sea . Royal Navy Commander Anthony Courtney was struck by the potential capabilities of former S - boat hulls , and John Harvey - Jones of the Naval Intelligence Division was put in charge of the project . He discovered that the Royal Navy still had two S - boats , " P5230 " and " P5208 " , and had them sent to Portsmouth , where one of them , " P5230 " ( ex - " S130 " ) , was modified to reduce its weight and increase its power with the installation of two Napier Deltic engines of 3000 hp apiece . In the interests of deniability , a former German S - boat captain , Helmut Klose , and a German crew were recruited to man the S - boat . They operated under the cover of the British Control Commission ' s Fishery Protection Service , which was responsible for preventing Soviet navy vessels from interfering with German fishing boats and for destroying stray mines . Royal Danish Navy . In 1947 , the Danish navy bought twelve former Kriegsmarine boats . These were further augmented in 1951 by six units bought from the Royal Norwegian Navy . The last unit , the P568 Viben , was retired in 1965 . Royal Norwegian Navy . After World War II , the Norwegian Navy received a number of former Kriegsmarine boats . Six boats were transferred to Denmark in 1951 . Survivors . There is just one surviving S - boat , identified as " S - 130 " . " S - 130 " was purchased and towed from Wilhelmshaven , Germany to the Husbands Shipyard , Marchwood , Southampton , England in January 2003 , under the auspices of the British Military Powerboat Trust . In 2004 , " S - 130 " was taken to the slipway at Hythe , where , under the supervision of the BMPT , she was prepared and then towed to Mashfords yard in Plymouth , England to await funding for restoration . In 2008 , " S - 130 " , having been purchased by Kevin Wheatcroft , was slipped across the Tamar River and set up ashore at Southdown in Cornwall to undergo restoration work involving Roving Commissions Ltd . As of June 2012 , this work continues and includes an S130 Members ' Club . Built as hull No . 1030 at the Schlichting boatyard in Travemünde , " S - 130 " was commissioned on 21 October 1943 and took an active part in the war , participating in the Exercise Tiger attack and attacks on the D - day invasion fleet . According to Dutch military historian Maurice Laarman : In 1945 , S - 130 was taken as a British war prize ( FPB 5030 ) and put to use in covert operations . Under the guise of the " British Baltic Fishery Protection Service " , the British Secret Intelligence Service MI - 6 ferried spies and agents into Eastern Europe . Beginning in May 1949 , MI - 6 used S - 208 , ( Kommandant Hans - Helmut Klose ) to insert agents into Lithuania , Latvia , Estonia , and Poland . The operations were very successful and continued under a more permanent organisation based in Hamburg . In 1952 , S - 130 joined the operation and the mission was enlarged to include signal intelligence ( SIGINT ) equipment . In 1954 / 55 , S - 130 and S - 208 were replaced by a new generation of German S - boote . S - 130 was returned to the newly formed Bundesmarine in March 1957 , and operated under the number UW 10 . Serving initially in the " Unterwasserwaffenschule " training sailors in underwater weaponry such as mines and torpedoes , she later became a test boat under the name EF 3 . S - 130 was on display in Wilhelmshaven , Germany , formerly used as a houseboat . Today " S - 130 " is undergoing thorough restoration in Southdown Marina , Cornwall , following purchase by the " Wheatcroft Collection " England . Variants . The " Schnellboot " design evolved over time . The first had a pair of torpedo tubes on the fore deck . Wartime types were : Specification . Other AA armament carried on different models included two or more pintle - mounted MG - 34s , 3 . 7 cm Flak 42 ( S - 100 ) and 8 . 6 cm RaG M42 ( " S - 100 " ) or , rarely , a " quad 2 cm flak " mount .