- Sidepower bowthrusters, world leading manufacturers of bow & stern thrusters.The homepage of Sidepower bow thrusters by Sleipner are chosen by many of the world leading boat manufacturers, including Princess, Sunseeker, Fairline, Hallberg Rassy, Storebro, Nauticat, Guy Coach, Ferretti, Queenship, Windy, Nimbus, Grand Banks, Nidelv, Nord West, Najad.side-power.com