depth limit. what happens if the plane is beyond that depth? don't they design submersibles to go a little further than their capabilities? >> sure. they have a certain margin so it doesn't go right to the margin of capability and implode. it has limits. it can't go infinitely deep and the ocean gets quite a bit deeper than it does at this particular spot. in the event it is much deeper than what it has been operating at today they are going to have to call in other pieces of equipment that can go in deeper. and unfortunately those cease to exist. >> do you think we will see manned subs down there, something like the alvin manned research submarine. >> i think eventually we will when we are in the retrieval phrase. right now we are talking about complementing the search and the only one capable of that has sonar and photography capabilities. that is what i would expect to see next if they don't see