Display of Ports
Ports are shown on the map by several different symbols. An "anchor" icon is shown if a port is vacant. A "locked anchor" is shown if the port is blockaded. When a fleet is in a port, the port is shown as a ship's wheel. If ships are being constructed in a port, it is shown as a spinning ship's wheel.
A province which has a port, or which will have a port when colonized, is called a port province. All port provinces are coastal provinces, but not all coastal provinces can have a port. It's obvious when settled provinces are port provinces: they show a map symbol (see above). To determine if an unsettled coastal province is a port province, select it. The depiction in the neutral province screen will show some water for port provinces. (In province.csv, port provinces have a nonzero value for PortXPos.)
To create a port in an unsettled port province, you must successfully colonize it. You don't have to do anything special to create the port itself; it is automatically created when the first successful colonization of the province happens.
Effects of Ports
The primary function of ports is in resupplying fleets. Whenever a fleet enters a port, all fractional attrition that the fleet has accrued, and its "months-at-sea" variable, are reset to zero. Ports also allow countries to build ships; ships may only be built in cities with a port.
There are some other rules which involve ports:
- most countries require a port to gain any colonists
- countries with protestant or reformed port cities receive bonus merchants
- ports allow armies to embark faster
- fleets with passengers can disembark them immediately upon stopping in a port
- an enemy port can be blockaded, reducing trade for the enemy and doubling supply for its enemies.
- ports increase the naval support limit.