MM43 thanks for the links.
Not wishing to criticize what the experts are doing, just recall a TV program where Ballard was searching for a wreck whose position was roughly known but they couldn't find it in the clutter with side scan. They found cruising an ROV along the bottom they eventually found a debris trail (things fall out on the way down), which led them to the main wreck.
Really I'm wondering if this method is practical in this case and if it might save some time, especially if the wreckage has floated outside the main search area.