Fish

• Leafy sea dragon
  Leafy sea dragon
  The leafy seadragon or Glauert's seadragon, Phycodurus eques, is a marine fish in the family Syngnathidae, which also includes the seahorses. It is the only member of the genus Phycodurus. It is found along the southern and western coasts of Australia. The name is derived from the appearance, with...
  
   (Phycodurus eques)
• Weedy sea dragon
  Weedy sea dragon
  Phyllopteryx taeniolatus, the weedy seadragon or common seadragon, is a marine fish related to the seahorse. It is the only member of the genus Phyllopteryx. Adult weedy seadragons are a reddish colour, with yellow and purple markings; they have small leaf-like appendages that provide camouflage...
  
   (Phyllopteryx taeniolatus)

Military

• Operation Sea Dragon (Vietnam War)
  Operation Sea Dragon (Vietnam War)
  Operation Sea Dragon occurred during the Vietnam War and was a series of American led naval operations beginning in 1966 to interdict sea lines of communications and supply going south from North Vietnam to South Vietnam, and to destroy land targets with naval gunfire, as well give CIA agents in...
  
  , a military operation
• MH-53E Sea Dragon, a helicopter
• USS Seadragon
  USS Seadragon
  Two ships of the United States Navy have borne the name USS Seadragon, named in honor of the seadragon, a small fish more commonly called the dragonet....
  
  , two ships of the United States Navy
• Kairyu class submarine
  Kairyu class submarine
  The was a class of midget submarines of the Imperial Japanese Navy, designed in 1943–1944, and produced from the beginning of 1945. These submarines were meant to meet the invading American naval forces upon their anticipated approach of Tokyo.-History:...
  
   (海龍 "Sea Dragon"), a class of Japanese submarines

Other

• Sea Dragon (rocket)
  Sea Dragon (Rocket)
  The Sea Dragon was a 1962 design study for a fully reusable two-stage sea-launched rocket. The project was led by Robert Truax while working at Aerojet, one of a number of designs he created that were to be launched by floating the rocket in the ocean...
  
  
• Sea Dragon (roller coaster)
  Sea Dragon (roller coaster)
  The Sea Dragon is a junior wooden roller coaster located at Jungle Jack's Landing in Powell, Ohio.The coaster was built by the Philadelphia Toboggan Company and began operating in 1956. It recently celebrated its 50th birthday in 2006. The Sea Dragon was originally called Jet Flyer, but changed...
  
  
• Sea Dragon class ROUV
  Sea Dragon class ROUV
  Sea Dragon class remotely operated underwater vehicle is a class of Chinese ROUV used to perform various underwater tasks ranging from oil platform service to salvage and rescue missions, and it is a class of ROUV developed in People's Republic of China with the deepest diving capability: up to...
  
  , a remotely operated underwater vehicle developed by China
• Sea Dragon (computer game)
• A zooming technology by Seadragon Software
  Seadragon Software
  Seadragon was a team within the Microsoft Live Labs. Seadragon is a web optimized visualization technology that allows graphics and photos to be smoothly browsed, regardless of their size...
  
   (acquired by Microsoft in 2006)
• Sea monster
  Sea monster
  Sea monsters are sea-dwelling mythical or legendary creatures, often believed to be of immense size.Marine monsters can take many forms, including sea dragons, sea serpents, or multi-armed beasts. They can be slimy or scaly and are often pictured threatening ships or spouting jets of water...
  
  , a mythical creature
• A fictional creature in the Majipoor novel series
  Majipoor series
  The Majipoor series is a series of novels and stories by Robert Silverberg, set on the planet Majipoor. The setting is a mixture of elements of science fiction and fantasy...
  
  
• A version of the pirate ship
  Pirate ship (ride)
  A pirate ship is a type of amusement ride, consisting of an open, seated gondola which swings back and forth, subjecting the rider to various levels of angular momentum....
  
   amusement park ride
• The Dragon in the Sea
  The Dragon in the Sea
  The Dragon in the Sea , also known as Under Pressure from its serialization, is a novel by Frank Herbert. It was first serialized in Astounding magazine from 1955 to 1956, then reworked and published as a book in 1956...
  
  a novel by Frank Herbert