Previously when helicopters have ditched in the North Sea they have been recovered by a dive support vessel using its main crane or if close enough to a platform, the platforms crane has been used. It would usually be done in a single lift so I'm guessing the lift bags are being used to move the wreckage further away from Blackrock for the safety of the recovery vessel. Even though the water depth is 40 meters, the wreckage is only 60 meters from the rock which would be quite close, even for a vessel with 'dynamic positioning' such as the Grainneuaille -particularly in a lazy Atlantic swell.