What is this symbol on my chart?

[Mike B]

I had the same plotter on my 361 and have traveled the upper and mid portions of Chesapeake Bay and all the way down Delaware Bay and had never seen it. Wont even begin to guess at what it might be.

 

[Navigate_us]

The most likely reason for this 'symbol' is an error by Navionics in the digitization of the chart. Have you asked them?

 

[Ross]

Down load this chart page. I would have posted it but it is too large. http://makingmaps.owu.edu/blogs/NauticalChart1957_Dangers.pdf

 

[dilligaf368]

Sandbar that moves

I will attempt to attach a photo I took of my Raymarine chartplotter yesterday when it displayed a symbol that I do not understand. (It's the symbol directly ahead of my boat.)It looks like the dorsal fin of a shark. Maybe there are sharks in the Tennessee River??!!

Chart 1 as others have quoted you look at for the answer to the puzzle.
I think what you see on the chart is a small area that the depth changes and moves around as in sandbars that change as the water volume changes and swirls changing the bottom depth.
Dilligaf

 

[agaliha]

My "shark" looks the same at all zoom levels. I have also seen the same symbol in a section of the river downstream about 20 miles. I can't find any reference to a "snag" in any of the references. Unlikely since it was 40 feet deep when the photo was made.

Looks like the Loch Ness theory is best!

 

[Ross]

Try to hang out there when a large tow goes by heading up river. See if you get big waves.

 

[Ron20324]

Where the white depth goes offscreen to the upper right- is there a river that comes in there and maybe causes tubulence where the "fin" is"? Like where the Potomac hits the Chesapeake Bay?

 

[Buck420]

This would be the "Greg Norman" chart symbol. It indicates the direction to the nearest golf course for boaters, who, frustrated w/ their chartplotters, might want to become even more frustrated golfers. It can be turned off by touching the chartplotter w/ a putter moving at a high rate of speed.

 

[agaliha]

Ron,
Logical question...the white area is a small creek tributary. Not likely to cause much in the way of current or shoaling.
Thanks,
the other Ron, "Agaliha"

 

[agaliha]

Ross,
Thanks. I didn't see anything like my "shark" on this page.
Agaliha

 

[higgs]

Don't you guys know anything?

i thought everyone knew this marked an atomic submarine base.

 

[Dan Johnson]

Hey Mike...

Head north like you were going back to Georgetown and pass inside (east of) the red marker at Plum Point Shoal and see if the shark fin pops up! I've seen some real turbulance at mid tide change in closer to shore there where it really humps up on the charts.

 

[SeaTR]

You guys are having waaaayyyy too much fun with this one... looks like spring launching days can't get here soon enough!!

I served on a nuclear submarine...the base didn't look anything like that!!
;-)

 

[Ron20324]

Jimmy Hoffa's headstone?

 

[Buck420]

I'd like to apologize for my earlier irreverent remark.
On a more serious note....
If one turns the chartplotter clockwise 90deg, the mark will be immediately seen as the internationally recoginized symbol for ... "gimmie a viagra"
and, continuing to turn the chartplotter an additional 180deg., reveals the equally well recognized symbol for "tanks for da viagra, mon".
It's all clearly explained in "Chart #2".