Fornelli Passage

North Sadinia Fornelli passage is a narrow channel between mainland Sardinia and the island of Asinara.

The method for safely negotiating the channel uses a navigational technique know as transits and leading lines. Transits are when two objects appear to be in line, one behind the other and a leading line drawn on a chart is a line which passes through both objects and then extended.

Fornelli Passage chart In this case markers on land have been specifically built to provide the necessary transits and the leading lines (drawn in pink) on the electronic chart show the course to follow and when the other pair of transits are in-line astern to change course for safe passage (depths in metres and tenths).