A Weather Working Day is not simply about whether bad weather delayed the vessel. The Vorras shows why the distinction matters: the wording defines what kind of time counts as laytime in the first place.
A Weather Working Day is not simply a day on which bad weather did (or did not) delay your vessel.
That distinction is easy to miss when calculating laytime, that's why it easier to think of WWD as describing the type of day (or period of time) that counts toward the contractual laytime allowance.
The question is therefore not necessarily:
“Did the weather actually stop this vessel from working?”
The better question is:
“Was the weather during this period such that the relevant cargo operation could have been carried out?”
A useful illustration comes from The Vorras (1983):
It was a port charter, so the vessel did not need to be alongside the berth in order to become an arrived ship. Having reached the usual waiting place within the port, she was able to tender NOR even though the berth was still occupied by another vessel. During part of that waiting period, however, the weather was such that loading could not have taken place anyway.
One might instinctively argue: “But the weather did not cause the Vorras’ delay. The occupied berth did.” But the Court of Appeal took a different approach.
The charter allowed “72 running hours, weather permitting.” The weather qualification described the time that constituted the contractual laytime. So, if the weather was such that a vessel of that type could not have loaded, that period was not “weather permitting” time, even though the occupied berth, rather than the weather, was the immediate reason why The Vorras was not actually loading.
That is the conceptual key:
Weather working terminology is descriptive, not merely exceptive.
It defines what kind of time counts, rather than simply providing relief where bad weather can be proved to have caused an actual interruption.
Put more simply:
Don’t only ask what stopped the vessel, but first ask what kind of time the charterparty says should count, because that small distinction can make a very large difference to a laytime calculation.
VLCC volumes fell as Hormuz disrupted traditional Gulf flows, but longer Atlantic-to-Asia voyages absorbed more vessel time. That has supported freight despite fewer barrels moving — but the effect could unwind quickly if trade routes normalise.
Iran asked ships to pay for passage through Hormuz. Now the US is proposing its own charge for providing security. The bigger concern is not the price, but the precedent: once free transit through an international strait becomes negotiable, the principle itself starts to weaken.
Oil prices are falling as the market prices a reopening of Hormuz, but tanker rates and insurance are telling a less comfortable story. Cargo is starting to move again, yet ships remain scarce and the physical system is still far from normal.