Diving expert on difficulties of searching sunken yacht off Sicily

How heroic Sicily rescue mission became recovery operation as Italian authorities announce they have taken four bodies from the water with one more remaining on tech tycoon Mike Lynch's sunken superyacht and a further missing passenger unaccounted for

Diving expert reveals the difficulties being faced by emergency services searching sunken yacht off Sicily. Simon Rogerson, editor of Scuba Magazine, says poor visibility will be a major factor to take into account.