Here’s a new one, at least for yours truly. A glance at chart 11489 reveals that #18, the marker front and center in Captain Hardy’s message below, marks a hard swing in the Amelia River/AICW channel, a short hop south of Fernandina Beach.
A conversation with the dockmaster at nearby Fernandina Harbor Marina as of 4/30/10 confirmed what I suspected, namely for the last three days there have been unusually low tides along the northeastern Florida coastline. I was told as least one foot below the usual levels. So, I’m sure these water levels contributed to the problems described below, but, nevertheless, there is also clearly an AICW shoaling problem near #18!

Subject: Shoaling near Fernandina Beach
Cruising News: We ran aground heading north today approaching R18 as you turn the corner on the Amelia River towards Fernandina Beach. It was low tide and our chart plotter showed 12 ft in the area where we and another boat were aground. A motorboat kindly ‘waked’ us and we got off. We draw 5ft. The other boat had to wait for the tide to rise. The deeper water was on the red side however we had to cut very close to the green can at the turn to stay afloat.
Harriet Hardy

We were in the parade of the sailboats yesterday slowly heading north on the Amelia River (4). It was approaching low tide and as we went under the bridge at m720. We were amazed at how low the water was in the Amelia Island Yacht Basin. I don’t think any boats could have gotten out. The lead boat ran aground, the other 3 passed to port, then at R18 another went aground, so we again passed to port but still we ran agound, once we were off we continued to favor the red side and had plenty of water’¦the other 3 sail & the powerboat continued on the green side. There was a very low spot in the middle of the channel. Pick either side but don’t go down the middle between R18 & R16.
We were in the parade of the sailboats yesterday slowly heading north on the Amelia River (4). It was approaching low tide and as we went under the bridge at m720. We were amazed at how low the water was in the Amelia Island Yacht Basin. I don’t think any boats could have gotten out. The lead boat ran aground, the other 3 passed to port, then at R18 another went aground, so we again passed to port but still we ran agound, once we were off we continued to favor the red side and had plenty of water…the other 3 sail & the powerboat continued on the green side. There was a very low spot in the middle of the channel. Pick either side but don’t go down the middle between R18 & R16.
karenbut@aol.com
Capt. RL& Karen

Just wanted to confirm the above observations regarding depth in the ICW just south of Fernandina Beach. We draw 5′ and touched bottom several times during our transit northbound when we were just south of Red #18 in the Amelia River. Our paper and electronic charts showed depths in the 12 foot range at MLW. We were transiting at low tide during this event. A `Towboat US’ operator stopped by after he had just finished towing a sailboat that had run aground in this same spot. He advised us to stay as far east towards shore when going north from Green #3 towards Green #1 and Red #18 on the river to avoid the shoaling in this area. He then would line up as a range Green #1 and Red #18 and then would honor Green #1 to continue the turn north. After the turn he advised heading straight towards the paper mill and favoring the eastward side of the ICW at least as far as the Fernandina Harbor Marina. We were able to follow his directions without further mud bouncing. He shared that since Hurricane Fay ‘“ this area has been a problem at low tide. Our recommendation would be to transit this area at mid ‘“ to high tide depending on your draft.
Fair Winds, Beth Bauer aboard S/V Adagio

And further confirmation of shallow water:
Sunday, January 20 2013
Southward at mile 719 between Red 18 and Green 3 had little over 4 feet at low tide. This is a wide channel so I swept across looking for more water and did not find any.
Ray Schmidt

Click Here To Open A Chart View Window, Zoomed To A “Navigation Alert” Position on the AICW/Amelia River