Buoyant Moored Device
This type of device floats on the surface of the water or below it. It is moored to the seabed by either a taught or loose mooring system. One example of this type of device will be discussed, the Edinburgh or Salter Duck. The Duck team is led by Professor Salter at Edinburgh University.
The Duck is shown in the figure below. Ducks work by independently rotating about a long linkage; this maintains its stability by out spanning wave crests. The front edge of the duck matches the wave particle motion. In moderate seas, the more cylindrical back portion creates no stern waves but when the weather is bad these parts shed energy through wave making to the rear. The device requires a depth of at least 80 metres and uses a system of weights and floats to give almost constant tension in the mooring cables.
The Duck is shown in the figure below. Ducks work by independently rotating about a long linkage; this maintains its stability by out spanning wave crests. The front edge of the duck matches the wave particle motion. In moderate seas, the more cylindrical back portion creates no stern waves but when the weather is bad these parts shed energy through wave making to the rear. The device requires a depth of at least 80 metres and uses a system of weights and floats to give almost constant tension in the mooring cables.