Could I just ask if anyone knows or has any experience in what level of equipment is being used to sweep the seabed? I presume the search teams are scanning the sea floor for debris and not just concentrating on the surface? It's not the deepest water in the world. Can under water devices cover a large area or is it a slow process to search an area in detail enough to detect parts of aircraft? I'm starting to wonder if any things been missed, particularly in the vicinity of the last known position.