WIBON looks like a small charterparty abbreviation. In practice, it can decide whether a week at anchorage is chargeable demurrage or simply waiting time at the shipowner’s cost.
WIBON means whether in berth or not. It is often read as a broad permission to tender NOR from wherever the vessel happens to be: the berth is occupied, the vessel is waiting, time starts, demurrage runs.
That is not quite what it does.
WIBON addresses one specific problem: the absence of an available berth. In a berth charter, the vessel is usually an arrived ship only when it reaches the berth. If no berth is available because of congestion, WIBON may allow NOR to be tendered from the waiting place instead of waiting until the berth clears.
The key word is available. If the berth is free but the vessel cannot reach it because of fog, weather or navigation restrictions, WIBON does not automatically shift that risk to the charterer.
In The Kyzikos, the vessel arrived at Houston under a Gencon charter containing WIBON. The berth was free, but fog closed the pilot station and the vessel could not proceed for three days. The owners tendered NOR and claimed time.
The dispute reached the House of Lords, which held for the charterers. The reasoning was narrow: or not in WIBON meant not in berth because no berth was available. It did not mean not in berth because weather made the approach impossible.
Fog remained a navigation risk. WIBON did not move it.
NOR starts laytime only if the vessel has arrived at the required place and is ready to work. Those facts must be true when the notice is tendered, not later after inspection, paperwork or conditions improve.
An invalid NOR may mean laytime never starts. If laytime has not started, the demurrage claim may disappear with it.
WIBON is useful. It is not magic. It protects against the absence of an available berth. It does not turn fog into charterer’s risk just because five letters appeared in the charterparty.