The White Flag, firing ranges and the Ice

White Flag of Peace. While it flies nothing can start a sea battle with you, and you start none (ashore you fight normally).

Cannons. Every gun has an optimal band in its reach (the coloured band in the firing fan): inside it shots hit hard; too far out and they scatter and weaken; inside 12% of the reach the guns will not bear. The Demi-cannon and the Basilisk are the sawn-off shotguns (heavy, slow to reload, short reach, best close in); the Culverin and the Long Nine are the rifles (quick to reload, long reach, a little lighter).

The Ice. The ring of ice mountains round the world is a solid wall from 47.4 km out. Run into it and your ship runs aground: half your durability is torn away and you are thrown back. Only Truth's Gate, due north, is open.

Weather is one sea for everyone: the same storm in the same place for every captain, and thunderstorms and gales raise the chance of sea perils.