Ile de Planier lies 5.5 miles SSW of Ile Tiboulen and is fringed with rocks and foul ground. It is low, flat, and inconspicuous from a distance. A light is shown from a structure, 62m high, standing on the island. A rock, with a least depth of 1.3m, lies about 0.2 mile E of the E end of the island.
A bank, with a least depth of 13.2m, lies about 1.1 miles ENE of the island. The sea breaks heavily over this bank and vessels should give it a wide berth.