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From: DAVE HEAD
Date: 29-04-08
Time: 08:31
[ Iasked Dave if the reef balls he sent me pix of were in a reef area or on open btm.And if they wer stable. His reply:
"Hi Wade They are in a region with reefs, in fact this one [and more later] are behind a reef parallel to the shore, where they are protected from major waves/swells. They are supplementary at this stage. The location is for easy access for our students [and local kids] so they can see with their own eyes what reefballs are all about. Later we are looking to establish a new reef on a flat featureless bottom anywhere from 10 to 20 metres deep. Stability? Various designs were tested in waves tanks before a final design was used. In practice they have survived hurricanes in the Caribbean in as little as 23 feet of water without moving while surround reefs were damaged. Our one at Whangawehi has been thru a winter- exposed to the open sea [except for the outer reef] and has not moved an inch. Two thirds of the weight is on the lower third and the side holes direct wave/current/surge energy up thru the top hole. Closer to the shore for erosion control they can be pinned to the seafloor. More details at www.reefball.org <http://www.reefball.org> and two other reefball linked sites.
Last changed: 29-Apr-2008