Neptun may refer to:
Nine ships and a naval base of the Royal Navy have been named HMS Neptune after the Roman god of the ocean:
A spy ship or reconnaissance vessel is a dedicated ship intended to gather intelligence, usually by means of sophisticated electronic eavesdropping. In a wider sense, any ship intended to gather information could be considered a spy ship.
HSwMS Småland (J19) is a Swedish Halland-class destroyer. She and HSwMS Halland were the only ones built of their class. Two more ships were ordered but they were never completed.
The Halland-class destroyers were two ships built for the Swedish Navy in the 1950s. Four ships were planned, but the second pair were canceled. Two modified ships were exported to the Colombian Navy. These vessels were general purpose surface combatants.
The Neptun-class submarine was a Swedish submarine class built by Kockums. The first submarine was launched in 1942 and a total of three submarines were built: HSwMS Neptun, HSwMS Najad and HSwMS Nacken. The class was decommissioned in 1966.
HSwMS Sjöormen (Sor), Sw. meaning sea serpent, was the lead ship of the Swedish submarine class Sjöormen, project name A11.
Sweden played a role of major importance during the Cold War, despite not officially participating. Sweden's location made it an ideal base of operations for both the Soviet Union and the United States. Sweden was never invaded throughout the war, mainly due to their strong defensive power - ranked among the top five in the world at this time.
HSwMS Neptun is the second of three Näcken-class submarines, built to operate in the Baltic. Neptun entered service in December 1980. The next year she was involved an international incident when the Soviet submarine U 137 ran aground outside Karlskrona.
Several ships of the Swedish Navy have been named HSwMS Neptun, after the Roman god of freshwater and the sea:
Several ships of the Swedish Navy have been named HSwMS Näcken, named after the mythological water spirit:
Several ships of the Swedish Navy have been named HSwMS Uppland, named after Uppland province:
Several ships of the Swedish Navy have been named HSwMS Halland, named after Halland province:
Several ships of the Swedish Navy have been named HSwMS Najad, named after the mythological water spirit:
Several ships of the Swedish Navy have been named HSwMS Belos, named after the mythological king of Egypt:
Several ships of the Swedish Navy have been named HSwMS Stockholm, named after the city of Stockholm:
Several ships of the Swedish Navy have been named HSwMS Helsingborg, named after the city of Helsingborg:
HSwMS Sjöbjörnen (Sbj), Sw. meaning sea bear, was the third ship of the Swedish submarine class Sjöormen, project name A11.
HSwMS Najad is the lead ship of her class of submarine for the Swedish Navy, project name A14. She was launched at the Kockums shipyard in Malmö, Sweden, on 13 August 1979, and completed and commissioned into the Swedish Navy on 26 June 1981.
HSwMS Halland (J18) was the lead ship of the Halland-class destroyer. She and HSwMS Småland were the only ones built of their class. Two more ships were ordered but they were never completed.