NETHERLANDS | Tuesday, 4 July 2006 | Views [477]
Operating the 'sluice' between two lakes, one which is about a metre higher than the other. If you want to take your boat from one lake to the other, you enter the sluice on one side, close the gate behind you and then slowly let the other gate open so the water flows in and lifts or lowers you to the level of the lake that you're entering.