A safe berth is a window,
not just a place.

Close a harbour watch

1. Select an arriving vessel. Read its length, draft, cargo, service duration, arrival, deadline, and contract priority.
2. Review tide heights and effective depth across the vessel’s entire service window, rather than only its first slot.
3. Choose a berth and starting cell. The game checks clearance, berth length, compatible cargo equipment, closure notices, and collisions.
4. Assign every vessel, then close the watch. The report compares your plan value with a solver-verified optimum.

What changes plan value?

Twenty-four harbours, three chapters

Every watch is its own authored harbour with its own quays, tide curve, arrivals, and operating notice. No watch is a renamed or reshaped copy of another one, and the campaign tests prove it. Tide school teaches depth, length, gear, and timing across eight harbours. Commercial promises adds booked start windows, priority contracts, and tighter deadlines across eight more. Working harbour closes quays for maintenance across the final eight. All 24 boards are solver-checked and every service promise in them can be met. Daily and generated relief watches are recorded separately.

Spring tide working

Switch on Spring tide working before taking a watch and the same harbour is rebuilt as a harder problem: a competing surge vessel arrives at the top of the watch wanting the same quay gear, and every service promise tightens by one slot. Each spring-tide harbour is solver-verified before it is dealt, and its result is recorded on its own shelf, so a spring result never overwrites your standard record. On a standard watch, taking the first safe cell for each vessel in turn is usually close to the best plan. On a spring tide it is not.

Reading a refusal

Whenever a vessel is selected, every cell that cannot start its service is marked with its own glyph and hatch pattern, and the legend under the board names the rule each mark stands for: before arrival, past the booked start, quay too short, wrong cargo gear, quay closed, not enough water, or the berth is already in use. A cell can break more than one rule at once, so every failing rule is listed together, counted, and repeated on hover, on focus, and in the message line when the cell is chosen. No rule is signalled by colour alone. Cells already inside a service window are striped and say which vessel holds them and until what hour.

Reading the two depth sums

Selecting a vessel writes out both sums in the vessel panel. Effective depth is the berth’s charted datum plus the tide at that hour. Required depth is the vessel’s draft plus the day’s clearance allowance. A berth is safe for a vessel only while the first stays at or above the second, for every hour of the service.

Where the value went

Every assignment states its own arithmetic as it lands: the service value, the exact cost of any waiting hours, whether the promise was met, and the preferred-quay bonus. Closing the watch repeats those clauses vessel by vessel, then compares the plan with the solver-verified best. The comparison names which of your vessels lost value and at which hour, and points to one direction to try. It never prints the verified plan.

Sharing and the daily strip

Copying a harbour log first shows the exact text that will be copied, with its own copy button and a Copied confirmation, so a browser that blocks the clipboard still leaves the log on screen. The harbour office lists the last seven archive dates with a filled dot and the value scored on the days you played.

Undo, redo, and the walkthrough

Every assignment can be undone and redone, so exploring an expensive-looking plan costs nothing. The first watch you open runs a three-step walkthrough that can be skipped and is never shown twice. Press ? at any time for the full keyboard reference.

Questions from the harbour office