|The upgrading of a Mermaid underwater vehicle|
de Haan, D. (1993). The upgrading of a Mermaid underwater vehicle. ICES Mar. Sci. Symp. 196: 140-142
In: ICES Marine Science Symposia. ICES/Reitzel: Copenhagen. ISSN 0906-060X, more
Behavioural responses; Environmental surveys; Fishery sciences; Fishing gear; Gear research; Trawl nets; Underwater vehicles; Viewing underwater; Marine
Dutch research on development of direct observation techniques started with the purchase of an underwater towed vehicle of type "Mermaid Explorer" in 1985. Targets for further development were observation of a wider range of fishing gears, with speeds up to 7 knots, and inspections of the marine environment requiring low-speed operation. A feasibility analysis showed the potential of an increase in magnus rotor performance. The single towing mode will be extended by a propelling mode (hovering mode). The two modes are to be interswitched without paying back. Performance measurements on several rotor configurations were conducted as part of the vehicle design process. A cross lay-out with four rotors reached the greatest depth in the shortest amount of time. A spherical rotor appeared to be ineffective.