I'm not sure of the year, but there were a couple times that we broke away from our preferred Horizon because Moorings had a better boat available. We had chartered with Moorings prior to that & were always able to use the tanks so I was surprised to see it. Then when we went back to Horizon they were doing it too.
Perhaps the first was the time we chartered the new, unnamed boat from Moorings. Our first BVI charter was 07/08 (Christmas/New Years) so it wouldn't have been 6 years ago that this happened, though!