How charter party congestion clauses split queue delay risk
Most disputes over anchorage delay don't turn on whether the vessel was waiting. In the fixtures that end up in a demurrage claim, both sides usually agree the ship sat outside the port for nine days. The argument is over which clause governs that wait, because that clause decides whose laytime clock was running the whole time.
Port charter party vs berth charter party
Start with the basic split, because it decides everything downstream. Under a berth charter party, the vessel is an "arrived ship" only once it's in berth, or at the loading or discharging place named in the fixture. If the berth isn't free, the vessel sits at anchor on the owner's time. The owner carries the congestion risk until a berth opens up.
Under a port charter party, the vessel is arrived once it reaches the port, often defined as the customary anchorage or waiting area, regardless of berth availability. Notice of readiness can be tendered from anchor, and if the vessel is in all other respects ready, laytime starts running against the charterer even while the ship is still swinging at anchor waiting for a slot.
That one distinction is why two fixtures on the same port, same week, same congestion, can land the demurrage bill on opposite parties.
WIBON, WIPON, WCCON: the clauses that decide who pays
Most modern dry bulk and tanker forms don't leave this to the port/berth label alone. They layer on "whether in berth or not" (WIBON), "whether in port or not" (WIPON), "whether customs cleared or not" (WCCON), and "whether in free pratique or not" (WIFPON). Each one strips away a condition that would otherwise have to be satisfied before NOR counts.
A vessel fixed WIBON can tender valid NOR from the anchorage even on a berth charter party, as long as it has arrived within port limits and is in every other sense ready to load or discharge. Add WIPON and even the port-limits requirement softens; NOR can go in from outside, at the customary waiting place for that port. Stack enough of these clauses and the practical effect mirrors a port charter party even though the base form reads as berth.
This is the part that catches traders out when they're reading a recap fixture note rather than the full charter party text. "WIBON" buried in the laycan clause changes who is paying for the queue, and it changes it quietly.
Reachable on arrival and the owner's warranty
The counterweight is the "reachable on arrival" or "always accessible" warranty, which some charter parties attach to the berth itself rather than the port. If the owner has warranted the berth reachable on arrival and congestion then holds the vessel off that berth, the delay can fall back on the owner regardless of what the NOR clause says, because the warranty was breached independent of when laytime technically started. This is the clause charterers lean on when a port is known for queues and they don't want to inherit someone else's backlog.
The two provisions, NOR wording and berth warranty, don't always point the same direction. A fixture can give the charterer a port charter party that starts the clock at anchor and still hand the owner liability for the queue if the berth warranty was breached. Reading one clause without the other is how parties end up arguing past each other at the demurrage stage.
Why the clause only matters once you know the queue exists
None of this allocation does a trader any good if the first sign of congestion is a laytime statement arriving weeks after the fact. The clauses tell you who pays once the facts are established. They don't tell you the facts are developing in the first place, and by the time the agent's telex confirms a queue, the vessel has usually already burned the better part of the delay. A charterer working several fixtures into the same discharge port needs to see the anchorage count building on its own, before the paperwork catches up, which is the gap a daily anchorage vessel count is built to close.
If you're negotiating laytime exposure into a fixture this week, it helps to know what the queue at that anchorage looks like before you sign the clause that decides who pays for it.