At 1.3 miles in 24 ° of the tip of Sant Ambroggio, a little rock, totally insulated, covered with one meter of water, is marked by a buoy north light.
It can be hard to spot against the light. But generally in the day the presence of small fishing boats reported this shoal that extends 200m south of the buoy and is only covered 0.8 to 3m of water.
By rough seas, we locate the most dangerous waves that break there. It is not uncommon that the buoy is moved or carried away after a storm.
By night the trap buoy Algajola is marked by a white light shining with a short range of 6 miles.
It is possible also guard this pitfall by browsing the white sector (079] to 234]) fire (3 12 sec bursts) of Ile Rousse visible up to 15 miles.