Where have you seen the best visibility ever seen?

[Digger54]

Best vis for me had been Blue Grotto near Williston, Florida, USA. Water was so clear you got the distinct impression that there was no water there. Other divers looked like they were hovering in mid-air. A narced diver (unlikely at BG's depths) might think they could remove their reg and mask and take a breath of fresh air.

I'll post one of my pix when I get to the office. For now, here's a pretty good example from a google search:

http://www.scubajax.com/where/images/blue_grotto/sunlight.jpg

 

[TSandM]

The best viz I've ever seen is effectively infinite, and that's in the cenotes in the Yucatan. The water is so clear, you don't know it's there. The dark stops your field of view before the visibility does.

The best salt water viz I've seen was in Cozumel, where we jumped off the boat and could see the whole wall and the sandy bottom, over a hundred feet below us.

 

[deeper thoughts]

The best viz I ever saw was at Palancar

 

[dave4868]

Methinks we have some BSers on this thread. Unless of course the word visibility is being abused.

Theoretical Maximum Secchi Depth

If you could lower a Secchi disk into absolutely pure water, the theoretical maximum value would be between 70-80 meters (230-262 ft).

Secchi Records

Deepest Recorded Secchi Depth
80 meters on October 13, 1986 in the Weddell Sea, near Antarctica (W.W.C. Gieskes, C. Veth, A. Woehr-mann, and M.Graefe, EOS, 1987). Citation courtesy of Hendrik Buiteveld

"about 70 meters:" is reported in the Sargasso Sea, using a 1.2 m disk. Mahon Kelly, (Personal Communication)

66 meters (217 feet) in the Sargasso Sea (Taber and Dubach, 1972)

53 m (174 ft) in the eastern Mediterranean (Berman et al. (1985)

44 m (144 ft) was obtained in Crater Lake, Oregon, using a 1 m diameter disk. Larson (1972) At the same time, Doug recorded 39 meters (128 ft) with a 20 cm disk.

Perhaps horizontal viewing is different from vertical viewing from the surface.

Heck, in my experience, vis varies substantially depending on the elevation and direction of the sun, just to mention one factor. The eyes' accomodation to low light could be another.

Check out Peter Brueggeman's page on Antarctic vis reports of 300 to 600 feet average in Spring, up to 800 feet.

Diving Under Antarctic Ice

Dave C

 

[aic007]

The best viz I've ever seen is effectively infinite, and that's in the cenotes in the Yucatan. The water is so clear, you don't know it's there. The dark stops your field of view before the visibility does.

The best salt water viz I've seen was in Cozumel, where we jumped off the boat and could see the whole wall and the sandy bottom, over a hundred feet below us.

I'll second the cenotes, They are absolutely stunning. and if it were possible to get to a section long enough, you could probably see for 1/4 mile. No movement, and the clearest water I have ever seen. I can see why people could get hooked on caves if they are all like the cenotes.

When we dove them the DM had us cover the lights at sections where he knew a room with sunlight was coming up and it was like floating in space, and then the light starts to creep in and it is one of the wildest feelings/experiences I had diving.

 

[Jrock1062]

Tomeck those are incredible pics was there any marine life there

 

[miketsp]

Agreed.
There are estimates and there is evidence, and the two might not coincide.
..snip..
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I have to call BS on some of the distances given in the article you referred to.
There are plenty of articles on the net where the maximum range visibility calculations derived from molecular scattering have been backed up by optical measurements using photometers and lasers on long tubes of ultrafiltered pure water.
Here is just one example of how scattering coefficients are measured.

http://optics.physics.miami.edu/ken/RefPapers/029_BVSV_AO_1998.pdf

What many people refer to as vis is nothing more than residual luminosity with no possibility to make out any details. While there is a narrow light transmission window with low attenuation the statistical scattering by the water molecules totally distorts the original image.

 

[dave4868]

I have to call BS on some of the distances given in the article you referred to.
There are plenty of articles on the net where the maximum range visibility calculations derived from molecular scattering have been backed up by optical measurements using photometers and lasers on long tubes of ultrafiltered pure water.
Here is just one example of how scattering coefficients are measured.

http://optics.physics.miami.edu/ken/RefPapers/029_BVSV_AO_1998.pdf

What many people refer to as vis is nothing more than residual luminosity with no possibility to make out any details. While there is a narrow light transmission window with low attenuation the statistical scattering by the water molecules totally distorts the original image.

If we're talking about the definition of visibility that divers might rely on, details of the large luminous object moving in the distance may not be important.

"Hey, there's something moving over there, probably my buddy. I'll swim over and see for sure...."

I'd say that a low criteria for defining visiblility is more useful to the diver in most circumstances, unless one is diving among a herd of strangers....

Dave C

 

[dannobee]

Interesting thread. A guy giving a presentation at our dive club goes to Weddell Sea, Antarctica every year and said the horizontal vis was at least 1000 ft. The world record vis using the Secchi method is listed here, so in either case, this place has the best vis.

The video he shot was simply amazing. It looked, literally, as if he was walking on some desert landscape, with the bottom of the ice looking like overcast clouds. In the middle of the video there was what appeared to be a tiny speck moving across the screen. After a few minutes we realized that the speck was a diver approaching us. Judging by the diver's size, he was at least 300-400 ft away and was as clearly visible as someone walking down the sidewalk. Whatever the vis was, either horizontal or vertical, it was the clearest water that I've ever heard of.

He did say that every year he'd try to leave before Christmas because after that the vis dropped markedly to "only" 300-400 ft. :11:

The ice was 10-15 ft thick. An interesting video that he shot was of the divers doing a "safety stop" by taking off their fins, then walking around the bottom of the ice, inverted.

Water temp was 28 degrees.

 

[Walter]

I've seen great visibility in lots of different places. Some of them almost always have great viz, while others rarely do. The place I've personally had the best viz was actually in the Gulf of Mexico 28 miles off Redfish Pass at a site called The Crack. The water was glassy. Except when they broke the surface, dolphins riding our our bow appeared to be moving through the air. After we anchored, another boat came up beside us, it looked like it was in the air. Barracuda hovered all around the area, they all appeared to be in the air. The only down side was when we hit the thermocline at 50 ft, we moved from air clear water to gray and only about 20 ft of viz. I've dived in great viz in Cayman, the Bahamas, Cozumel, Bonaire, the Keys, Blue Grotto (and other springs), Roatan and others, but none of them copmpared with that day in the Gulf.

A narced diver (unlikely at BG's depths) might think they could remove their reg and mask and take a breath of fresh air.

Why do you think divers are unlikely to get narced at 100 ft?