Ten years ago, Maersk Tankers did one of shipping’s first green retrofits on one of its VLCCs.

The 318,400-dwt Maersk Ingrid (built 2012) was fitted with a Becker Mewis Duct, a propeller boss cap fin and just about every energy-saving device available on the market at the time.

The aim of the trial — funded in part by the Maritime & Port Authority of Singapore’s Green Technology Fund — was to generate fuel savings of between 7% and 8%.