In the mid 1970s, after towing the semi-sub "Sedneth 701" from the North Sea to just off Setubal, Portugal, we were running the anchors and setting the "piggy back" anchors. A helicopter was flying out to the rig with some Portuguese government dignitaries, including an admiral of the fleet, when a thick fog came down. The pilot was flying blind and the rig was giving the pilot the wrong directions. After too long in the air, and fuel getting low, he set down on the sea.
We were tasked with picking up a heli-tank and giving the helicopter fuel. The fog was lifting, and as we went to the helicopter a frigate and a corvette came racing out of the naval base in Setubal. We had to stand-off, as every time we went in the direction of the helicopter the frigate would cut across our bows with the forward 4" gun pointing at us. I've worked on 4.5" guns, but when looking down the wrong end of a 4" gun it looks massive! Eventually the warships were convinced that we were friendly, and after a boat load of marine commandos checked us out we were allowed to proceed.
The odd blue cast is due to the combination of light, and fog which was lifting.
The helicopter was secured on the stern roller in readiness for the fuel transfer.
The helicopter pilot was embarrassed and somewhat shocked. He said that if he hadn't put down in the water when he did, he would have flown right into the cliff face!
The officials refused to go back in the helicopter, so we took them to the rig, and they went up in the basket. Quite an adventure for them, and us, but one that almost went horribly wrong!