Portolan

Charting an unknown sea

Portolan is a PC sailing and surveying game set in 1821. You start with a completely blank chart and fill it in by sailing, taking measurements and recording what you find. There are no coastlines or currents marked for you: every detail on the chart comes from your own observations.

Your ship has four instruments. A compass and log record course and speed, which you use to estimate your position. A sextant gives latitude from the sun at its highest point, but provides no longitude and cannot help on cloudy days. A thermometer measures sea temperature each hour, helping you find current boundaries. A lead line measures the depth of the bottom when it’s within 150 metres.