Perdido Pass, extending between Florida Point and Alabama Point, is easily distinguished from offshore by State Route 182 highway bridge across its entrance with two openings. The fixed span over Perdido Pass Channel has a clearance of 54 feet. The fixed span over Cotton Bayou Channel has a clearance of 41 feet. The dredged entrance channel leads from the Gulf through Perdido Pass to a fork at the highway bridge; thence into two channels, one leading N into Terry Cove and Johnson Cove and the other leading E into Bayou St. John. The entrance to the pass is protected by a jetty on the W and by a combination weir and jetty on the E; the top of the weir is submerged 6 inches at mean low tide. Numerous sunken wrecks are in the approach to the pass. In October 2006, the controlling depth was 5.2 feet (8.2 feet at midchannel) in the entrance channel to the intersection of the east and west channels, thence 4.9 feet (8.3 feet at midchannel) in the west channel leading to Terry and Johnson Coves, thence 6.9 feet (7.4 feet at midchannel) in the east channel leading to Bayou St. John. The channels are well marked; a lighted whistle buoy off the entrance marks the approach.
The Intracoastal Waterway in the lower part of Perdido Bay is reached from Perdido Pass via a marked channel through Bayou St. John. In May 1982, shoaling to 6 feet was reported in Bayou St. John between Daybeacons 6 and 8. An overhead power cable with a clearance of 59 feet crosses the channel leading to Terry Cove and Johnson Cove, about 0.4 mile from State Route 182 fixed bridge. Several small-craft facilities are in the coves and Cotton Bayou, on the W side of Perdido Pass 0.7 mile above the entrance. (See the small-craft facilities tabulation on chart 11378 for services and supplies available Old River enters Perdido Pass from E between Florida Point and Ono Island. In May 1982, a reported depth of 5 feet could be carried through the river with local knowledge. The Florida-Alabama State boundary passes through Old River. A fixed highway bridge with a clearance of 24 feet crosses Old River about 1 mile East of Perdido Pass