Sea Link I & II, Johanson’s mid-water manned submersible The Johnson- Sea Link (JSL) I & II are owned and operated by Harbor Branch Oceanographic Institution, Ft. Pierce, Florida. At 23.6 ft long, 10.9 ft high and 8.3 ft wide, these highly maneuverable submersibles can dive to a depth of 3,000 ft (915 meters) and travel at a maximum speed of one knot. Edwin Albert Link, engineer, inventor, and friend of Harbor Branch founder Seward Johnson, working at Harbor Branch, designed and built the JSL in 1971, at Mr. Johnson’s request. Harbor Branch constructed the JSL II, which is virtually identical to the JSL I, in 1975. The JSL has two separate pressure hulls and can accommodate four people. Aft compartment occupants enter the sub through a bottom-facing 20 inch-wide hatch. The front chamber, which contains the sub’s controls, is a 5-ft-diameter sphere made of five-in thick, clear acrylic. It provides a panoramic view for the pilot and one observer. Because acrylic is a good insulator and hampers conductivity of cold ocean temperatures, the front compartment actually requires air conditioning. The second chamber, the stern compartment, houses another crewmember and a second observer. The occupants have access to two side view ports and a video monitor.   The evolution of specialized equipment such as manipulator arms, suction devices, and rotary plankton samplers has made it possible for crewmen to accomplish almost any work from within the subs that once was done only by divers. The Johnson Sea Link submersibles are further outfitted with active sonar, laser aimed still and broadcast quality video cameras, and Harbor Branch developed xenon arc lights. The arc lights approximate sunlight, illuminating underwater scenes in true color and near daylight conditions, even in the darkest seas.   Technical specifications, Johnson Sea Link: Weight in air (lb/kg): un known Payload in air (kg): un known Dimensions (L*W*H feet/meter): 23`6*8`3*10`9/7.2*2.5*3.1 Propulsion: a few thrusters 7?, all battery storage operated Speed (sub/knots): 1.0 highly meneuverable Range (sub n/miles@knots):4 hours operational time Diving depth (feet/meter): 3,000/915 Complement: 2 pilot, 2 researcher Construction: exterior still and video cameras, video camera rests on a platform that can extend up to 8 ft from the vessel, 1*manipulator/robotic arm can manipulate multiple sampling devices, a suction tube uses a vacuum to “slurp” up delicate samples, a claw and scoop are used to snare other small creatures and collect rock samples. Back to History Index   Image Country Year Description United States Johnson Sea-Link, research submersible for science, dive no.950 on 10 Sep' 1980, Houston TX, Sep' 16, 1980 Congo, Rep. 1993 Sea Link I, Manned submersible