Abstract: A steerable bow thruster (12) system is located substantially within the pontoons (20) of a semisubmerged vessel (10) exclusive of a rotating nozzle (42) which is located on the upper side of the pontoons. The rotating nozzle can turn in any direction and allows the steerable bow thruster system to thrust forward, aft and side to side and in any direction in between to allow the semisubmerged vessel to maneuver freely and without the assistance of the main engines. To minimize draft and to prevent ecological harm, the nozzles are installed on top of the pontoons allowing the pontoons to act as a barrier to keep thrust wash from disturbing shallow ocean bottoms and reefs over which the vessel may be operating. The propelling means may be shrouded to prevent harm or injury to swimmers who may be in the water. A rudder (44) may also be coupled to the thruster nozzle to provide directional control for the semisubmerged vessel when it is underway at higher speeds.

Abstract: An elevating platform attaches at the stern of a small waterplane area twin hull vessel (swath) that can be raised and lowered from a position nearly level to the vessel's deck to a position nearly level to the waterline. The platform allows convenient movement of people and equipment from the deck of the vessel to the surface of the water. Such movements may be required for either immersion in the water or removal onto another vessel or shore-side structure such as a dock. The platform attaches to the trailing edge of the vessel's struts and elevates vertically along the struts to the desired level.

Abstract: A process for the production of lubricant oil range hydrocarbon having increased viscosity index by oligomerization of lower olefins over medium pore shape selective acid zeolite catalyst. The preferred oligomerization process is conducted using 50 ppm to 5 weight percent of water vapor as cofeed, based on olefin and acid ZSM-5 zeolite.