Bottom Finder Pics

[skinneej]

Originally Posted by Tyson Brown

Yes. Ones that are shallow enough, you can dive and feel the upwelling.

Also, they're huge deep holes surrounded by higher seafloor. If they weren't blowing water out, they would quickly be filled with sediment.

That makes sense, but I got a book from a commercial guy here and they aren't divers. Spot is in like 100'. I haven't found a spring yet though, only a ledge nearby. My numbers are Loran conversions, so there could be something still out there... It's just always struck my curiosity.

[primalpete]

HurricaneBK,

I think I know what wreck that is. We were going to dive it two weeks ago but instead hit one less than a mile away. Solid thermocline around 150 and no one was home. Did run into a cubera in the 30's in 150 the next dive but he was too smart to get close too.

[Tyson Brown]

Originally Posted by skinneej

That makes sense, but I got a book from a commercial guy here and they aren't divers. Spot is in like 100'. I haven't found a spring yet though, only a ledge nearby. My numbers are Loran conversions, so there could be something still out there... It's just always struck my curiosity.

Springs could go "dry" and fill in, and LORAN conversions are fraught with inaccuracy.

Also maybe they just thought a ledge was a spring based on the sonar profile, who knows. Or maybe someone gave *them* the numbers and said it was a spring.

Probably your numbers are just off. Look at a bathymetric chart to see if there are any noticeable holes nearby. Try the Navionics web app (google search)

[HeadHunter]

Originally Posted by skinneej

Dan, question for you... I've seen the word "spring" used before in commercial books. Is this really a freshwater spring dumping into the ocean? Also, how is this determined\verified?

I don't think so. Talked to quite a few knowledgeable people over the years, all say there are no fresh water springs offshore on the West Fl shelf. I think comm fishermen started calling them "springs" and it just kinda stuck. A lot of them have tidal flow but I've never dove one with fresh water coming out of it.

[HeadHunter]

Big Cubera cave.

[Tyson Brown]

Originally Posted by HeadHunter

I don't think so. Talked to quite a few knowledgeable people over the years, all say there are no fresh water springs offshore on the West Fl shelf. I think comm fishermen started calling them "springs" and it just kinda stuck. A lot of them have tidal flow but I've never dove one with fresh water coming out of it.

I should have prefaced my statements that it was logic and secondhand info I was relying on, and that I'd never dove one.

Dan would know a lot better than me.

However, I still don't see how they would stay holes with hurricanes and storms moving sand and silt around.

[HeadHunter]

Dean got this Cubera off it.

[Tyson Brown]

From article "Submarine Groundwater Discharge Along West Florida Shelf"
http://soundwaves.usgs.gov/2009/07/

This vent (Crystal Beach Spring) is one of many known offshore springs along the coastal sections of Pinellas, Pasco, Hernando, and Citrus Counties; however, according to a spring survey conducted by the Southwest Florida Water Management District in 2002-03, Crystal Beach Spring is the only spring discharging large volumes of relatively fresh groundwater; the others appear to have stopped flowing. What keeps this spring flowing while so many others in the area have become extinct?

[HeadHunter]

Originally Posted by Tyson Brown

I should have prefaced my statements that it was logic and secondhand info I was relying on, and that I'd never dove one.

Dan would know a lot better than me.

However, I still don't see how they would stay holes with hurricanes and storms moving sand and silt around.

You make a good point Tyson. I think for those exact reasons are why we don't seem to have any in shallow water. In skinny water the sand from storms could easily fill one in. The "springs" in 200' + probably never get any significant filling in from even a major storm. Just too deep for the bottom to be significantly affected from waves.

There's one I've dove a lot in 130' that somedays has no movement, other days has sucking in movement and I've also seen it blowing out. Tidal surges would be my guess.

The way I feel about it is that I've never seen one with fresh water flowing out of it. If I saw one doing it tomorrow, then I'd have no problem changing my views on it!

[HeadHunter]

Cool spot, very very good Cubera bottom.

[HeadHunter]

Lots of fish.

[Tyson Brown]

Also, FWIW, some of the "springs" are known to be sinkholes, which may have been aquifer caverns before they collapsed.

[HeadHunter]

Totally agree, I think most are sinkholes. Makes sense.

[skinneej]

Originally Posted by Tyson Brown

Springs could go "dry" and fill in, and LORAN conversions are fraught with inaccuracy.

Also maybe they just thought a ledge was a spring based on the sonar profile, who knows. Or maybe someone gave *them* the numbers and said it was a spring.

Probably your numbers are just off. Look at a bathymetric chart to see if there are any noticeable holes nearby. Try the Navionics web app (google search)

My numbers are way better than any bathy charts... Anyway, yes, I know conversions are off, but this ain't my first rodeo. They are usually off up to about 250' or so. The trouble is, when you have a lot of structure in one area, it's hard to tell if you are looking at what the original mark was or you just happen to be looking at the next piece of structure over.

[skinneej]

Originally Posted by HeadHunter

I don't think so. Talked to quite a few knowledgeable people over the years, all say there are no fresh water springs offshore on the West Fl shelf. I think comm fishermen started calling them "springs" and it just kinda stuck. A lot of them have tidal flow but I've never dove one with fresh water coming out of it.

Cool. Thanks for the info. I figured you would indeed have some perspective on it.