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Encyclopedia of Marine and Energy Technology

Small waterplane area twin hull (SWATH)


catamaran with unconventionally shaped hulls: two submarine-like floating bodies lie deep under the water surface and thus create the required buoyancy. On the waterline the vessel offers the least possible working surface (water plane area) so that the backward forces are low. In this way, the movement of the ship caused by external forces is only slight. As a result, the vessel lies exceptionally stable and quiet on the water, even in case of heavy sea. The US Navy commissioned the SWATH type ship KAIMALINO that has been operating successfully in the rough seas off the Hawaian islands since 1975.

In 1999, the German pilots started to work with two 25m SWATH pilot tenders, followed by a 50m SWATH pilot station ship ELBE built in 2000 by the German shipyard Abeking & Rasmussen. Both the station ship and the pilot tenders have excellent seakeeping performance and manoeuvring capabilities. During adverse weather conditions, the pilot transfer service can continue even at a waveheight of 3.5m (wind force 10-11). See also SWATH research vessel PLANETUseful website: