Bistol Siddeley artist's impression of a future ocean-going Air Cushion Vehicle (ACV) circa 1964.
Source: "Gas Turbines for ACVs--Past, Present and Future" Flight International November 19, 1964
http://www.flightglobal.com/pdfarchive/view/1964/1964%20-%203245.html
[The] ACV borrows the bow-thruster propeller idea now current on large liners and features a large fan in the forward superstructure giving port or starboard sideways thrust for better controllability in harbours and confined waters.
Source: "Gas Turbines for ACVs--Past, Present and Future" Flight International November 19, 1964
http://www.flightglobal.com/pdfarchive/view/1964/1964%20-%203245.html