Bottom Stains...no, no, not THAT kind...an Iron Hat???

[Jolly Mon]

I was snorkling off a barrier island in about 6 feet of water the other day. I suddenly noticed that the bottom sand had turned from the normal dirty, off white into almost a red, rusty color. It was really quite unusual. I started thinking about something I learned from some old time gold prospecters about "gossans" or the "iron hat". Gold veins are often associated with iron oxides and these oxides can leach out into the surrounding soil and stain it a rusty iron color. I started looking at the bottom again. The color change was really quite remarkable. Within a few feet the sand changed from off white to very nearly red. The width was nearly uniform...about 50 feet. The length was hard to determine, but was way too long to be any normal ship...I would guess about 200 yards or so. It was almost a straight line, 50 feet wide, 600 feet or so long, perpendicular to shore. There are no jetties in the area and no known large, modern shipwrecks. The area where I discovered this is at the tip of a barrier island near an inlet and has been undergoing some very significant erosion over the last few years. I know this may sound crazy, but I was thinking that a ship with enough iron on board might begin to stain the surrounding sand red and that the reddish color might spread with the longshore current into a pattern far longer than the original footprint. Has anyone ever heard of something like this?

 

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[stevemc]

I dont know where you are, but sometimes there are pipelines going offshore, maybe waste water, sewage, who knows what. They may be old and not used any more, or still used . I would think that is what it is. Many nav charts show cables and sometimes pipelines going out from shore. But yes, an iron ship would stain the sand. But it wouldnt be 600 feet long. Oh and WELCOME!!!!!!

 

[Jolly Mon]

Thanks, Steve. A pipeline is actually what I thought originally. There are none listed on the chart for the area and the island is uninhabited...there is really nowhere to run a pipeline too. It is perpendicular to shore and there just does not seem to be any reason to run a pipeline through the area. Another weird thing is that there was a Civil War Fort on the island....first Confederate and then Union. The island has suffered immense erosion since the 1860's and I know the fort was located very near the area of the stain. There was also major Union fleet action here throughout the war and there was a large battle between the Union fleet and the Confederate fort before it was captured. It is just kind of a strange place to find a stain like this, frankly.

 

[stevemc]

t could be a dredge pipe or pieces used to dredge a channel. I have found those under the sands. It could be civil war ships, hard to say.

 

[Southern_Digger]

Another possibility to consider... might be sewage algae that died out and stained the bottom. Fortunately, I have south Florida surf to search, snorkel, and in past times, dove for lobster and whatever else I might discover. I remember when I could look down in Miami River and see about four feet into the water. My father remembers when Miami River was much clearer; and grandad and great grandad remembers seeing it almost perfectly clear in many places as the tide replenished clean water. I also remember seeing bottom rocks at about 20-ft in Boynton Beach Inlet during the early 1960's.Unfortunately, not the same today and not even close in many places. For example beautiful Key Biscayne beaches get stained from this algae because the Miami Wastewater Treatment Plant is situated on nearby Virginia Key. The ocean bottom is stained by the algae. Treated water and emergency overflows drain into the ocean. Beaches are clean and white due to dredged sand from farther out. However, the water can get discolored and sometimes smells like watered down sewage--this is in the Atlantic, mind you. In fact, sometimes bacteria count gets so high that beaches are closed. When digging for u/w targets, it is not uncommon to unearth tampon tubes and actual rag pads. Pretty bad tourism I'd say if you measure your water quality by the number of tampon tubes per cubic yard of seawater. I rarely search there except during low, low tide; shower on exit and take a boiling shower at home. The bottom is stained in many places, brown to a reddish brown--not red tide either.

 

[Jolly Mon]

Here is an aerial shot. I am sure it is probably just a dredge pipe or maybe even of biological origin, but it just looks weird. It looks even weirder up close.

 

[stevemc]

I see. It is parralell to the shore, not perpendicular. Most likely the whole shoreline in that area will have that. It is most likely sediment as was mentioned prior. It also could be sediment from that creek. Maybe there was a sandbar off the stain and it ran through. Leaves that rot and runnoff can leave a rust type stain on things.