Port-Saint-Louis-du-Rhone is situated on the W side of the Golfe de Fos. The commercial port facilities occupy the banks of the Canal Saint-Louis, which connects the Golfe of Fos with the Grand-Rhone via a lock, aw well as the Bassin Saint-Louis located at the W end of the channel.The port is approached via the main entrance channel, which is dredged to a depth of 24m and extends WNW across the gulf. A fairway, 180m wide, leads W from the SW side of this entrance channel to the E entrance of Canal de Saint Louis. A jetty extends 1 mile E from the S side of the entrance to the canal. The canal is 90m wide at the surface, 32m wide at the bottom, and is dredged, along with the entrance fairway, to a depth of 7.9m. It leads 2 miles W to Bassin des Tellines and Bassin de Saint Louis.
The W end of the canal is connected to the Rhone by a lock. It is 135m long, with 19m of usable width, and has a depth of 5.5m at the sides and 6.9m in the center.
The port includes 2,840m of total quayage, which is situated in the basins and along the sides of the canal. The berths are 90 to 180m long and have depths of 4.5 to 8m alongside. There are facilities for ro-ro, LNG, tanker, and bulk vessels. Vessels up to 190m in length and 7.9m draft can be accommodated.