So what is your take on diesel fuel prices after 2020?

ALL Ships have to switch to ULSD when they cross an imaginary line at sea before entering a Port. This the reason that Tote and Crowley Maritime have just built tow ships that burn LNG. These ships run between ports on the US East Coast and Puerto Rico.

It is correct that ships can install a scrubber system (think huge DPF) but it is very expensive to install and also to maintain.

ALL, inland and Coastal Tug and Barges have been burning ULSD for many years, IIRC, we did the switch back in the early 90's.