The entrance to Chichester Harbour is flanked on both sides by extensive drying banks; West Pole, Middle Pole and East Pole Sands, the latter extending more than a mile seaward. These banks are not likely to be a problem for small boats except at low tide (so check your tide heights if you plan to sail over them).
A deep-water channel running between these banks to the harbour entrance is interrupted by a bar joining West to Middle Pole and East Pole Sands; this mobile feature varies in position and height and is periodically dredged. Chichester Bar is marked by the Bar Beacon, which is also where the information for the Chimet service comes from.
The most obvious structure at the harbour entrance is the West Pole navigational mark, which is a large 3-legged structure with a red top (which looks like a Fez).
The sea in this area can become very rough, especially with an onshore wind and an ebbing tide.