Assuming that the 2011 date is correct then it must indeed be LNG LOKOJA - arrived Gibraltar 12/6/2011 from Fos and sailed following day for Bonny

The other three sisters were all in/near the Indian Ocean on that date.

Thanks Ian, LNG Lokoja - and thanks Jan, LNG Kano must have arrived after Lokoja had sailed on the 13th.

After checking the LNG carriers with the lifeboat on the stern, the LNG KANO, was the only one, which was on June 16th at Gibraltar