The HNLMS Dolfijn (S808) ("Dolphin") is a Walrus-class, diesel-electric attack submarine currently (2013) in service with the Royal Netherlands Navy. The class is made up of four boats led by the HNLMS Walrus (S803) and includes the HNLMS Zeeleeuw (S803) and the HNLMS Bruinvis (S810). The Walrus-class is the only submarine type in service with the Royal Netherlands Navy and replaced the preceding four-strong Zwaardvis-class family of attack submarines appearing throughout the 1980s/1990s (of which two remain active as of 2013). The Dolfijn design is noted for its quiet operation and is capable of deep ocean service. Construction of the vessel was handled by Rotterdamsche Droogdok Maatschappij of Rotterdam, Netherlands (defunct in 1996).
The HNLMS Dolfijn displaces at 2,350 tons when surfaced and 2,650 tons when submerged. She is crewed by 50 personnel made up of officers and sailors divided into watches. Onboard suites include the Signaal/Racal AW07 surface search radar, a Thomson Sintra TSM 2272 Eledone Octopus sonar, a GEC Avionics Type 2026 towed array system and a Thomson Sintra DUUX 5 series passing ranging and intercept sonar system. The hull design features a running length of 68 meters with a beam measuring 8.4 meters and a draught of 6.6 meters. The hull is also of a noticeably faceted design instead of a traditionally smooth, rounded surface seen on other submarines. Interestingly, it also displays a rather unconventional "X" arrangement of its rudder planes as opposed to the more traditional "cross" arrangement seen elsewhere. The vessel manages centralized sail which is capped with various communication and sensor systems as well as the requisite optical systems. Dive planes are featured along the sides of the sail. Propulsion is served through a 3 x diesel engine / electric configuration developing 5,430 shaft horsepower to a single five-bladed propeller at the stern. A maximum speed of 13 knots can be achieved when surfaces and a 20 knot maximum speed can be reached when submerged. The vessel can reach depths of up to 300 meters.
As an attack submarine, the Dolfijn is appropriately equipped with 4 x 21" (533mm) torpedo tubes with up to 20 x Mk 48 (or NT37) series torpedoes ready-to-use. Additionally, she is equipped to launch the SubHarpoon surface-to-surface missile to contend with surface warship threats. The boat is also capable of launching naval mines as required. Despite its armament array, the Dolfijn has been primarily used as an intelligence-gathering platform by the Royal Netherlands Navy and the United Nations. The Dolfijn has actively participated in joint European/American exercises, most recently as a part of BALTOPS 2013 (BALTic OPerations 2013).
Since the 1990s, the Walrus-class has been in active operational service and have since entered a period of modernization to make the class more useful in offshore operations.