Michael Asberg assignor to AB Volvo Penta. Propeller drive unit Z drives thru bottom of hull used to regulate trim. Method and apparatus for reducing drag on a body. March 1998 Reslein. Surface effect vehicle .
Patent has excellent references to other surface effect information.
Lennart Brandt assignor to A.B. Volvo Penta Propulsion arrangement for marine vehicle . Jet drive that generates trimming forces. Donald E. Burg. Marine propulsor . Jet drive with gas at top of jet during high speed operation.