David, as far I have observed the fully discharged ships leave the port on a light draft, to carry out tank washing at sea, return to the loading berth, discharge the slops and take on a full load. We now have Zourva in the 7th Petroleum Dock. Recently the Samail discharged at MOT, moved out to sea, came back to the 7th Petroleum Dock, moved again to the 8th (BP Refinery), and then came came back in the Caland Canal. Most VLCC's will pick up their cargo from different jetties, may be they carry different grades of crude oil, or part of the cargo could be fuel oil too.

Why this one offloaded just a part cargo and then filled up again is beyond me, but there may still be some intricacies dealing with Iranian oil.

Unlike the Chinese one, this one seems not to have gone anywhere else, so it seems discharged and loaded in Rotterdam area:
5/3 arr Maasvlakte at 22.1m
7/3 moved to Europoort at 19.5m
12/3 to Rotterdam Anchorage 5 at 19.5m
15/3 arr Europoort at 19.5m
22/3 sailed Europoort for sea at 21.6m
23/3 passed Dover Strait at 22.1m [bunkers?]

Is it the practice to take in ballast water during unloading to maintain draft, and v/v on loading?

Kharg Island Oil Terminal from 11 Nov 2016 for 51 days, then arrived Falmouth Harbour for 2 hours on 12 Feb 2017, Rotterdam 5th - 22nd March, arrived Singapore 19th June 2017.

It could be that she moved on to antoher port for the discharging the remainder of her cargo. I shot her again on March 20th, now loading a full cargo in the 8th Petroleum Dock. So I assume that tihs picture shows her waiting to depart for her next port of call (Fawley?) only to return to Rotterdam to collect het next cargo, (most likely Russian oil, destined for the Far East)

Any idea if this ship discharged, according to her AIS her draught changed by 3m- does that sound realistic for a discharge for a vessel this size?