It was a routine trip out to a mobile barge named Global Sapphire. Prior to departure especially for mobile barges and FSO ships, the specific weather report containing the pitch and roll limits are scrutinised to determine if the barge is within safe limits for a deck landing. Just think about trying to land a helicopter on let's say....the Black Pearl tossing in the wake strirred by an angry Kraken. This is what we refer to as an exaggeration to depict a point. Pitch and roll limits exceeding 3 degrees would make landing the helicopter on deck hazardous. Global Sapphire's weather report stated the roll at 2.4 degrees. It wouldn't take much for that to swell to 3 or more.
The weather outbound was serene, with a healthy tailwind speeding us onward to the barge. Oh, I could use that, especially when it was my second running sortie after having done the 7 am muster to two rigs, as the sooner we got there, the sooner we would be home. Thankfully I was flying with a most placid aircraft captain. I did not serve with him in the air force, therefore there was no residual history on which to pick in order to show me who the better pilot between us was. 40 miles out and the stable atmosphere manifested in carpet cloud at 2800 feet.
The ten-minute prior landing call to check on the current weather at Global Sapphire revealed that the barge had a roll of 2.5 to 3 degrees. As it was colocated with Angsi Delta, we decided to carry out the passenger exchange on deck Angsi Delta instead.
As we descended to the lower atmosphere, it began to get gloomy with haze. Angsi was a pale skeleton against the grey background, and all that stood prominently was her raging erect flare emitting much soot above the plume of flame.
We trailed past the rig to set up for a running in on finals to land. All was going well when at just 300 feet above deck, the radio operator called out, " Tango Juliet, Angsi Delta here we have a stop-work alarm now, deck not clear for landing." I acknowledged the call and the captain executed a baulked landing, depressing the "go-around" button and climbing away from the approach. Just half an orbit later, I called in for an estimate of the delay. The radio operator replied that all was in the clear and we could land on deck.
As I was supposed to fly the leg home, the captain got down to supervise the passenger drop-off and pick-up while I stayed in the cockpit to give the passengers their welcome-aboard brief and make the all-stations departure call. I looked towards the right and there she was, miss Global Sapphire, tossing and twisting on what looked like a tempestuous sea. Odd, I thought. We approached to land in virtual nil-wind conditions. Why then was Global Sapphire so unstable? Perhaps because she was no different from any rescue boat, except that a helicopter platform was sewn onto her head, just above the bridge at the bow making her top heavy and with the propensity to behave like The Milkmaid from Aesop's fables.
I learned this day, what a 3-degree roll looks like. It was enough to make me dizzy, and I don't see myself even imagining a landing on anything like that.