Louisiana’s Coastal
Entrances, Inlets, & Passes

Whether you are making use of the Gulf Intracoastal Waterway (GIWW) or sailing coastwise along Louisiana’s Coast, there are literally hundreds of entrances, inlets, and passes between the Gulf of Mexico and the inside waters of Louisiana. Many only suitable for shallow draft vessels or local knowledge, but some can be considered navigable by most vessels. We are going to list only those that are important to accessing the Gulf Intracoastal waterway or that can be considered navigable for most vessels.

Louisiana Entrances, Inlets, and Passes

Open Down Arrow GIWW - Louisiana Entrances, Inlets, and Passes
The Rigolets to New Orleans

Chef Menteur Pass

Chef Menteur Pass, located 10.3 NM southwest of Rigolets Inlet. Provides access to the GIWW and Lake Pontchartrain.

Chef Menteur Pass

NOAA Chart #11371 - Lake Borgne and Approaches is suggested for the approach to Chef Mentuer Pass while NOAA Chart #11367 - Waveland to Catahoula Bay is suggested for the entrance.

The Gulf Intracoastal Waterway is found 1.5 NM above the entrance at (MM "22.9 EHL") near lighted beacon (Fl R 2.5s 17ft 4M "4").

Approach

The approach is marked by a lighted beacon (Fl R 4s 17ft 5M "2"). The approach is surrounded by shoals, but 6 feet can be carried with careful navigation and 5 feet can be carried over the shoals at most times.

Entrance

The entrance and pass is unmarked with reportedly good water bank to bank. Charted depths increase to 30+ feet mid-channel until reaching the Gulf Intracoastal Waterway.

Cautions

A new Gulf Intracoastal Waterway alignment channel crosses Chef Menteur Pass 1 mile SSE of the original Intracoastal Waterway crossing, but reports are of shoaling to 3 feet. Caution is advised.

Tides & Currents

The mean tidal range is approximately 1.4 feet.

Southwest Pass

Southwest Pass, the westernmost of the passes for the Mississippi River and the only one capable of deep draft vessels. Making use of the Mississippi River, the majority of the mid-west is accessible through this pass. From New Orleans, LA to the head of navigation in Minneapolis, MN and entrance to the Great Lakes via Chicago, IL.

Southwest Pass

NOAA Chart #11361 - Mississippi River Delta is suggested for the approach to Southwest Pass while the “Southwest Pass Inset” on the above chart can be used for the entrance.

Intersection with the Gulf Intracoastal Waterway happens at a number of locations off the Mississippi River depending upon whether you are eastbound or westbound beginning about 97.8 NM above the Southwest Pass Entrance.

Approach

The approach to Southwest Pass is marked by buoy (RW "SW" Mo (A) located at 28°52’39"N / 89°25’55"W), approximately 1.75 NM south of the entrance. Lighted buoys and ranges mark the approach.

Prominent on the approach is Southwest Pass Entrance Light (Fl 10s 122ft 12M at 28°54’21"N / 89°25’43"W) RACON equipped showing the Morse code equivalent of the letter "K" or (–·–).

Entrance

The entrance has jetties on both sides with a range leading in. The channel through to the intersection with the Gulf Intracoastal Waterway and well above New Orleans is deep (45+ feet) with good water available bank to bank with few exceptions. It is well-marked by lighted buoys and lighted beacons.

Cautions

Heavy Commercial Ship Traffic.

Tides & Currents

The current, so far as is known, can be depended upon to set nearly straight out from between the jetties, but cross currents can be present due to winds and seas. Tidal range at the entrance is typically about 1 foot.

Misc.

Intersection with the Gulf Intracoastal Waterway happens at a number of locations off the Mississippi River depending upon your direction of travel.

Algiers Navigation Canal Inlet

The Algiers Navigation Canal is located at MM "88.2 AHP": (97.8 NM above the Southwest Pass Entrance). It allows access to the GIWW when westbound. The canal has good water bank to bank and is crossed by (3) bridges, (1) fixed and (2) lift bridges. All bridges offer 100 feet of clearance.

The canal entrance is on the south side of the Mississippi River and intersects the GIWW at MM ("6.5 WHL" near lighted beacon (Fl (2+1) R 6s 20ft 3M).

Inner Harbor Navigation Canal

The Inner Harbor Navigation Canal entrance is on the north side of the Mississippi River and provides access to and is part of the Gulf Intracoastal Waterway. This inlet is for vessels eastbound on the GIWW.

The intersection with the GIWW takes place at MM "92.5": AHP located approximately 101.6 NM above the Southwest Pass Entrance or about 80.5 NM Above Head of Passes (AHP). The inlet is marked by (2) lighted beacons: Fl G 2.5s 30ft 4M "1" on the west side and Q R 40ft 4M "2" on the east side.

Cautions – When turning in from the Mississippi River, be aware of a stump awash (at 9.9 feet water level) about 10 feet out from the east bank.

Tides and Currents – Tides in this area are almost non-existent except at the lowest of Mississippi River Water Stages. Tidal currents likewise do not exist other than the currents due to the outflow of the river.

Harvey Canal

Located approximately 2.9 miles above the Crescent City Connector Bridges, it is marked by a traffic light to control entry. This canal is actually part of the Gulf Intracoastal Waterway with the Harvey Lock being MM "0.0." It marks the split between mileages measured East of Harvey Lock (EHL) and West of Harvey Lock (WHL).

The canal has good water bank to bank and is crossed by both bascule and fixed bridges with a minimum vertical clearance of 95 feet.

Open Down Arrow GIWW - Louisiana Entrances, Inlets, and Passes
New Orleans to Cameron

Cat Island Pass

Cat Island Pass is well marked with lighted buoys, daybeacons, and ranges. It has a controlling depth of 13’, but minimum depths of 10’ have been noted.

Cat Island Pass

NOAA Chart #11357 - Timbalier and Terrebonne Bays is suggested for the approach to Cat Island Pass.

Cat Island Pass intersects the Houma Navigation Canal 1.5 miles above the entrance. From the Houma Navigation Canal, the least depth reported was 10’ to its intersection with the GIWW at Houma, LA at (MM “59.6 WHL”), 36.8 NM above Cat Island Pass.

Approach

The approach is marked by buoy (RW "CI" Mo (A) located at 29°00’10"N., 90°34’06"W) 4.8 NM SSE of the entrance. The approach channel has a controlling depth of 16 feet and is well-marked with lighted and unlighted buoys.

Entrance

The entrance is likewise well marked with a controlling depth of 11 feet in the Bay Channel then 4.5 feet to the intersection of the GIWW.

Cautions

Numerous oil platforms exist within 2 NM of the approach buoy.

Tides & Currents

The mean tidal range at the entrance is approximately 1 foot.

Atchafalaya Bay Inlet

Atchafalaya Bay Inlet is located between Point au Fer Island to the east and Marsh Island to the west. It provides access to the GIWW and Morgan City, LA.

Atchafalaya Bay Inlet

From the entrance, a dredged channel leads to the Lower Atchafalaya River and on to its intersection with the Gulf Intracoastal Waterway is found at (MM “98.3 WHL”) 21.8 NM above the entrance.

Approach

The approach to Atchafalaya Bay is marked by a pair of buoys marking the outer end of the approach channel. (G "1" Fl G 2.5s) and (R "2" Fl R 2.5s) located at 29°10’42"N., 091°33’17"W) 14.8 NM SSw of the entrance. The approach channel has a controlling depth of 10 feet and is well-marked with lighted and unlighted buoys and beacons.

Entrance

The entrance is likewise well marked with a controlling depth of 14 feet in the Lower Bay Channel then 10.0 feet to the intersection of the GIWW.

Cautions

Numerous oil platforms exist within 1 NM of the approach buoys.

Tides & Currents

The mean tidal range at the entrance is approximately 1 foot.

Calcasieu Pass

Located 26.0 NM ENE of Sabine Pass, TX, Calcasieu Pass is a deep-draft entrance providing access to Cameron, LA, the GIWW, and Lake Charles, LA.

Calcasieu Pass

NOAA Chart #11339 - Calcasieu River and Approaches is suggested for the approach and entrance.

Calcasieu Pass intersects the Gulf Intracoastal Waterway at (MM “241.1 WHL”) 20.5 NM above the entrance near lighted beacon (Fl R 2.5s 17ft 4 M "92").

Approach

The approach is marked by lighted buoy (RW "CC" Mo (A)) located 25.6 NM SSE of the entrance at (29°20’01"N., 093°13’15"W). The approach channel is deep (with a project depth of 42 feet) and well-marked with lighted buoys. A lighted range is also available beginning at lighted buoy (G "27" Q G).

Entrance

The entrance is protected by jetties to the east and west that are marked on their outer ends by lighted beacons showing Q G and Q R repectively. It is likewise deep with a lighted range.

Cautions

Be aware of severe water turbulence in the vicinity of large vessels transiting narrow waterways. Strong cross currents may exist off the jetty entrance.

Tides & Currents

The mean tidal range at the entrance is 1.3 feet. Strong cross currents may exist off the jetty entrance.

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