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 (sĕm′ē-səb-mûr′sə-bəl, sĕm′ī-)
1. Any of various self-propelled water vessels designed so that most, but not all, of the structure is submerged, including vessels with decks close to the waterline for transporting large structures such as oil rigs and disabled ships, and vessels with minimal structure above the waterline for avoiding detection.
2. A seagoing, self-propelled barge that has partially submerged vertical legs attached to underwater hulls or pontoons and serves as living quarters and a base of operations in offshore drilling. In this sense also called semisubmersible rig.

sem′i·sub·mer′si·ble adj.


1. (Mining & Quarrying) nautical (of an oil rig or watercraft) that can put much of its bulk under water
2. (Nautical Terms) nautical (of an oil rig or watercraft) that can put much of its bulk under water
3. (Nautical Terms) nautical a watercraft that can put much of its bulk under water
4. (Mining & Quarrying) mining a shortened form of semisubmersible rig


(ˌsɛm i səbˈmɜr sə bəl, ˌsɛm aɪ-)

1. Also called sem′isubmers′ible rig′. a self-propelled barge mounted on legs supported by underwater pontoons, on which offshore drilling crews live and work.
2. of or for a semisubmersible.
References in periodicals archive ?
announced that its wholly-owned subsidiary Hong Hua Offshore signed a contract on October 31, 2014 with a unit of Malaysia-headquartered Jas Marine to build a European-designed semisubmersible mobile offshore drilling unit for around $320 million.
The company's fleet consists of one floating production facility and five drilling units (a drillship, a semisubmersible and three jackup drilling rigs).
Summary: The Southern Cross semisubmersible drilling rig has reached the Lambouka-1 well site offshore Tunisia, says ADX Energy Ltd.
Ensco's drillship and semisubmersible rigs successfully mobilized away from the storm and a flyover inspection indicates no damage to the Company's jackup rigs that were secured and evacuated ahead of the hurricane.
Agility Group has inked a deal with China Oilfield Services Limited (COSL) to deliver detail engineering for the integration of the drilling package onto their latest drilling semisubmersible unit, Hai Yang Shi You 982.
Atwood will be providing the Atwood Southern Cross semisubmersible offshore drilling unit to conduct the work program.
Jurong") construct another deep water semisubmersible drilling unit at Jurong's shipyard in Singapore.
Construction of the new accommodation semisubmersible will be to Keppel's proprietary SSAUTM5000NG design, having accommodation capacity of nearly 500 persons in one- and two-man cabins.
OL) for the use of the semisubmersible GSF Arctic II in the North Sea.
GE will supply electric power, propulsion systems and drilling drives for a new semisubmersible drilling platform HHI is building for Seadrill Ltd.
In addition, it is scheduled to take delivery of a new ultra-deepwater semisubmersible in 2009 and a new ultra-deepwater drillship in 2010.
Fourth Ultra-Deepwater Semisubmersible in Fleet and the Third of the ENSCO 8500 Series([R])