Abstract: A water-monitoring apparatus includes an anchor for holding on to a bottom of the water, a buoy for floating on the water surface, a reel mounted on the buoy and a tension and signal cable including a lower end tied to the anchor and an upper end tied to the reel. The tension and signal cable is wound on the reel. A control device is connected with the reel. When the water level changes, the control device rotates the reel, thus adjusting a length of the tension and signal cable extending from the reel so that the buoy always float on the water surface. A shallow-water sensor is carried via the buoy for detecting a first environmental characteristic and for producing a first signal representative of the first environmental characteristic. A deep-water sensor is connected with the lower end of the tension and signal cable for detecting a second environmental characteristic and for producing a second signal representative of the second environmental characteristic.

Abstract: An apparatus for monitoring presence of hydrocarbon-based fluid is disclosed. It includes a body and a sensing cable mounted on the body in a wave-like shape, thus forming a plurality of sensing sections for detecting a layer of hydrocarbon on water. When contacting hydrocarbon, each of the sensing sections generates a signal and the signals add up before transmission to a signal receiver through a signal line.

Abstract: A water-monitoring apparatus includes a frame installed by water. A reel is mounted on the frame. A cable including lower and upper ends is wound on the reel. A buoy is connected with the cable. At least one sensor is used to detect a water quality parameter and to produce a signal representative of the water quality parameter. The at least one sensor is carried via the buoy and electrically connected with the lower end of the cable. The reel can be rotated to adjust a length of the cable extending from the reel so that the at least one sensor can always be immersed in the water. A signal relay includes a first block electrically connected with the at least one sensor and a second block electrically connected with a monitoring station wherein the first and second blocks are connected with each other in a non-contact electric manner.