My family would travel every summer from the NY/NJ area to Martha's Vineyard for vacation. Of course, we'd have to take the ferry across from Woods Hole.
In the earlier days, the "Woods Hole, Martha's Vineyard and Nantucket Steamship Authority" ("Steamship Authority") actually still ran steamers back and forth (they're all diesel powered now). The last steamer in service (the SS "Naushon" , formerly the SS Nantucket), was fueled with #6 Bunker C. It had to be heated to 135˚F before it could be pumped off the truck. I happened to be there once as the Naushon was preparing to leave port for the first time that day and saw the #6 Bunker C truck delivering fuel to the vessel.
These days, the terminal itself gets a delivery of diesel fuel from the "Diesel Direct" truck 3 times a week. It appears to be delivered to a central storage tank underground. I am therefore curious as to how the fuel gets from that storage tank to the boats. I never see any of them fueling. Furthermore, for the boats that stay overnight on the islands, how do hey get fueled?
Woods Hole Terminal. The Diesel Direct truck usually gets there between 7:30a - 8:00a, MWF.
They probably refuel directly from a truck delivered at night. I bet they buy direct on long term contracts from the fuel distributor or maybe even further up the supply chain. Ships built to carry freight in regular runs have enormous fuel capacities and can go a long way before refueling.
When I worked on fishing boats, we refueled maybe once a month if the openings were short, and once a week if we had multi-day openings. I know the ocean going ships tried to stay topped off if their credit was good. When we refueled, we picked a time when there was no one else around. Usually at night around 10 PM or even later.