THE HELIPAD DECK AT THE STERN OF THE BARGE WAS COVERED WITH A LOOSELY SECURED ROPE NET AND WITNESSES REPORTED THAT AS THE HELICOPTER LIFTED UP TO A HOVER THE NET CAME UP 'CAUGHT ON THE REAR OF THE LEFT SKID.' THE ACFT WAS SEEN TO HOVER FOR A MOMENT WITH THE NET TANGLED IN THE LEFT SKID, THEN THE NET 'SUDDENLY LET GO.' THE ACFT WAS SEEN TO 'PITCH NOSE UP' AND BANK VIOLENTLY LEFT INTO A CRANE AND A DAVIT BEFORE IT FELL OVERBOARD AND SANK. ACCORDING TO A SURVIVING PASSENGER SEATED NEXT TO THE PILOT, AFTER THE HELICOPTER HOVERED FOR A MOMENT THE PILOT LEANED OVER AND ASKED 'ARE WE HUNG UP' JUST BEFORE THE HELICOPTER BANKED LEFT AND COLLIDED WITH THE STRUCTURES. BOTH OF THE HELICOPTER SKIDS AND OTHER WRECKAGE WAS FOUND CAUGHT ON THE DAVIT. EXAMINATION OF THE SKIDS REVEALED STRANDS OF THE ROPE MATERIAL CAUGHT IN BETWEEN THE BOLT HEAD AND SKID FLANGE FOR THE LEFT GROUND HANDLING BOLT.