East Coast Alerts

By Mel Neale

Cape May Inlet--Again?? They just dredged in January!
The following appeared in the Fifth District Local Notice to Mariners No. 14/05 Page 15 of 20 04/05/05

A U.S. Army Corps of Engineers survey dated 31 March 2005 indicates Cape May Inlet has shoaled to 9 feet, MLLW, 50 feet south of the centerline near the end of the south jetty. Chart: 12317.

Atlantic Intracoastal Waterway, Georgetown to Charleston, SC, Mile 410-464
The Charleston District of the US Army Corps of Engineers surveyed the condition of this section of the Atlantic Intracoastal Waterway in November and December 2004. The results are just now published in the April Monthly edition of the USCG Local Notices to Mariners, District 7,
Number 14-05. The Project Depth of this entire area is 12 ft; the channel width is 90 ft; depths given are for mean low water.

The survey included only the left outside quarter and the right outside quarter, from north to south. The depth of the middle 45 ft of width is left to our imagination, but one would optimistically hope that the middle is a little deeper than the outside quarters. The outside quarters are all in the single digits of depth, with most in the 7 to 8 ft range. The shallowest overall is the stretch below McClellenville with 4.9 ft on the left and 4.2 ft on the right. This is consistent with our observation that the centerline depth of this area was about 6 ft in November 2004.

The bottom line is that we all need to stay in the center of the channel, and expect depths a little deeper there than on the sides, but possibly not much. With 4 to 6 ft of tidal range, it helps to do this stretch on half tide and rising if you are a deep draft vessel. Without maintenance dredging for the AIWW, the situation continues to deteriorate.

Atlantic Intracoastal Waterway, Port Royal Sound, SC, to Fernandina, FL Mile 554-713
The Savannah District of the US Army Corps of Engineers has conducted a survey of the depths of the waters in this area. I won’t give all five pages of details, but will summarize the shallowest parts. If you want to see the whole report, which I advise, it is part of the March 29, 2005 USCG District 7 Local Notices to Mariners, Number 13-05. The dates of the surveys are Feb 18, 22-25 and March 3, 2005.

There are three depths given for most areas, the West Quarter, the Center, and the East Quarter. Most of the channels are supposed to be 150 ft wide, although narrow stretches like Creighton Narrows may be 90 ft wide, and sounds may be 300 ft wide. All have a Project Depth of 12 ft and all depths are for mean low water. This area has between 7 and 8.5 feet of tidal range.

The shallowest parts:

• Hells Gate, Mile 601.4 to 602.4, 6 ft centerline with 2.5 ft in the east quarter
• Florida Passage, Mile 605.9 to 608.5, 5.5 ft centerline
• Little Mud River, Mile 653.0 to 656.4, 6 ft centerline with 2 ft in the west quarter
• Altamaha Sound, Mile 656.4 to 660.1, 6 ft centerline
• Buttermilk Sound, Mile 662.1 to 664.5, 5 ft centerline with 2.5 ft in the west quarter
• Jekyll Creek, Mile 680.9 to 685.9, 5 ft centerline, 2 ft in the west quarter

Because this part of the AIWW is of low commercial value, it has had no scheduled dredging maintenance for several years and none is budgeted for the current fiscal year, nor proposed for FY 2006.

In Addition, the Alternate Protected Route bypassing St. Andrews Sound, NOT on the AIWW, Mile 686 to 701.1, controlling depth is 3 ft in the Umbrella Creek section. Project depth here is 7 ft, with 75 ft channel width.

This information is extracted from the USCG Local Notices to Mariners. We don’t give it to be used for navigation. You should consult the USCG Local Notices to Mariners.

Copyright 2004-2005 Tom Neale