Notice to Navigators: Southeast Rivers


LNM 06-22



This section contains information of special concern to the Mariner.



The U.S. Coast Guard Navigation Center is going to transition the Navigation Center website to a new, enhanced version in the first quarter of 2022. As part of this transition, URLs will be updated across the site including URLs linked to PDFs. Therefore, once the transition is complete, legacy site URLS will no longer function, including bookmarked URLs and URLs used in automatic downloading of data and/or products. Outdated URLs will automatically redirect to the home page of the site, and from there you will be able to easily navigate to your preferred page.

Below are a few of the “old”/new URL pairs listed for your convenience. Please note that the new URLs will not be active until we launch the new website. Of course, once it is launched, the new URLs will be available for re-bookmarking. As a reminder, these are top level URLs that may contain additional links that you use. This notice will be updated when the final launch date is determined, and another notice will be issued to notify you when the site goes live. Questions/concerns may be directed to the Local Notices to Mariners (LNMs) Current URLs: Replacement:

Light Lists Annual Publication Current URLs: Replacement:

Light List - Weekly Current URLs: Replacement:

Light List - Corrections Current URLs: Replacement:



In accordance with Section 7-11 of the Apalachicola, Chattahoochee and Flint Master Water Control Manual and the Jim Woodruff Lock and Dam and Lake Seminole Water Control Manual (Appendix A) dated March 2017, a 7-foot navigation channel will be supported via water releases on the ACF through May, 2022, when the composite storage for the system is in Zones 1 and 2. The composite storage graphic, which is updated weekly, can be viewed at the following website:

A 7.4-foot Blountstown stage is needed to provide a 7-foot channel on the Apalachicola River. River stages for the ACF system can be viewed at: Commercial mariners should schedule lockage appointments at the Jim Woodruff Lock by calling (850) 663-4692 or (229) 723-3482. George W. Andrews and Walter F. George Locks remain closed due to mechanical failures. Navigation Bulletins will be issued on a monthly and as needed basis throughout the navigation season. For further information, mariners can contact Ashley Kleinschrodt, at (251) 694-3726.


FL/AL/MS/LA - Uncrewed Surface Vehicle Operations

Commencing February 15, 2022 and continuing until March 30, 2022, SeaTrac Systems intends to deploy its Uncrewed Surface Vehicle (USV), the SP-48, for the purpose of ocean data collection. The USV will be launched at the Fort Desoto boat ramp in St. Petersberg, FL., from there it will be escorted by the SeaTrac chase boat to the area north of Egmont Key, where it will run systems checks before heading offshore. It will spend roughly 3 days, 15 nautical miles north west of Egmont Key before heading due west to Longitude 088-00-00.000W, to meet the loop current where it will run transects for several weeks. The SP-48 will be monitored and controlled remotely from the SeaTrac office located at 100 Hoods Lane, Marblehead, MA., 01945. The SeaTrac team will have their support boat, a 19-foot Ribcraft, on standby to assist the USV should it be necessary to intervene at any point during the nearshore portion of the mission. The SeaTrac team has lined up recovery options for the USV when it is further offshore should it have any critical systems failures. The operational area is bound by the following approximate positions:

  • Marker 1: 28-00-00.0N 089-00-00.0W,
  • Marker 2: 28-00-00.0N 082-40-00.0W,
  • Marker 3: 27-00-00.0N 089-00-00.0W and
  • Marker 4: 27-00-00.0N 082-40-00.0W.

The SP-48 is a 16-foot, solar powered, USV that is intended to operate persistently for up to months at a time for the purpose of data collection and monitoring applications. The USV weighs 650 lbs and has a cruising speed of 3 knots and a top speed of 5 knots. The USV is equipped with an Automatic Identification System transceiver, running lights and a yellow signal flag to aid in observability and is also marked with “Uncrewed” on the transom to clearly indicate the absence of personnel onboard. The pilot has real-time access to 360-degree cameras on board the USV for situational awareness which can be accessed through redundant communications links (cellular and satellite) for communications with and control of the vehicle.



Attached as an enclosure to this LNM is USACE Mobile District Notice to Navigation Interests 22-13, regarding channel conditions at L/D’s, along the Lower Tombigbee Waterway.



This section contains advance notice of approved projects, changes to aids to navigation, or upcoming temporary changes such as dredging, etc. Mariners are advised to use caution while transiting these areas.


FL - APALACHICOLA BAY TO LAKE WIMICO - Apalachicola Bay - Two Mile Channel

Due to shallow water in Two Mile Channel, the Coast Guard will be making the following change after April 5, 2022: Change Two Mile Channel East End Daybeacon 12 (LLNR-2910) in approximate position 29-42-45.100N/085-00-28.290W, to Two Mile Channel East End Buoy 12 (LLNR-2910), showing red nun.



This section contains information of general concern to the Mariners. Mariners are advised to use caution while transiting these areas.




FL - APALACHICOLA RIVER - Construction Operations

Continuing until further notice, construction is taking place on the Apalachicola River, just north of the Dewey M. Johnson bridge. A safety boat is underway in the area to assist in directing traffic. Mariners are urged to transit the area with caution.