Understanding Visibility

[UaVaj]

As scuba divers are always concern about visibility.

I like to categorize this. Since each region of the world has a different tolerance for visibility. To keep this on a level scale. Let's look at this from a recreational stand point. Perfect Visibility would = 130ft + and No Visibility would = 1ft

Please fill in the blanks as you see fit. Of course in feet of visibility.

Perfect or Crystal Clear = 130' +
Great or Excellent =
Good =
Fair =
Poor =
No Vis or Muddy = 1'

 

[UaVaj]

I will go first

Perfect = 130' +
Excellent = 90' +
Good = 60' +
Fair = 30' +
Poor = 10' +
No = 1'

 

[AbyssalPlains]

I dont get the point of this. Perfect visibility is more than 130 feet in my book, and why would 1 foot of visibility be equal to no visibility? In my book, 1 foot of vis is, well, 1 foot of vis. I have dived in zero foot vis and I can tell you, it is very different from 1 foot of viz. It's all relative - when I'm diving in San Diego and find 45 of vis, I would categorize that as "exceptional, once of a lifetime viz," but if I'm in the Red Sea, I would categorize that same visibility as "sucks a$$."

 

[UaVaj]

As you can see already. Visibility varies quite a bit among divers, regions, and whatever else.

Reason for using 130' as the top of the scale is becuase this is the max recommended depth where most recreational folks can reach. Reason for using 1' as no vis is becuase anything less is undiveable. At this point - you might as close your eyes shut and go 100% by feel.

 

[Papa_Bear]

Viz is nice and is measured by a 1 foot white disk until you can't see it! But you don't need X viz to have great dive! Photography is more depended on viz, but you always have micro! So to me I always want the best, but I will deal with what I get! And I agree zero is when you can only see IN your mask and that is a lot different from 1ft! Avalon Harbor Clean up last year was 1 to 2ft. we all brought up a lot of stuff!

 

[mpgunner]

I'll add my Puget Sound perspective:

Perfect = Still waiting for this
Excellent = 45+ (a great day)
Good = 30+ (a decent day)
Fair = 10-20+
Poor = 3-5 (Can I see my fins?)
No = < 1'

 

[Sas]

For local diving:

Perfect or Crystal Clear = 40m+ (I have never had more than 20m of viz though locally..)
Great or Excellent = 20m-40m
Good = 10-20m
Fair = 5-10m
Poor = 0-5m
No Vis or Muddy = 0m

There is a big difference between no viz and 30cm of viz I think. I've only had zero vis twice when diving, both dives started at about 1ft but decreased to not be able to see anything at all, and it made quite a bit of difference.

 

[kathydee]

Perfect or Crystal Clear = 130' +
Great or Excellent = 80+
Good = 80-45
Fair = 45-25
Poor = 25
No Vis or Muddy = 1'

I never dove below 25' vis (lembeh) or above 120' (sipadan) and all diving has been in Indonesia and Malaysian Borneo. I think I'm spoiled ;-)!

 

[RJP]

Reason for using 130' as the top of the scale is becuase this is the max recommended depth where most recreational folks can reach.

BTW - viz is generally HORIZONTAL distance, so the reason for your 130' cap is a bit off.

Here's what 150' of viz looks like in Stingray City...and in only 20' of water!

Here in NJ?

Perfect = requires a plane ride
Excellent = 70ft+ (an amazing day)
Good = 50ft (a great day)
Fair = 20ft (a typical day)
Poor = 10ft (at least I'm diving)
No = < 1' (should have played golf)

 

[spectrum]

I think of it in a more functional way and more in terms with my local New England diving.......

I can't see my buddy at 3 feet = Poor
I can see my buddy at 3 feet = Fair
I can see my buddy at 10 feet = Good
I can see my buddy at 20 feet = Very Good
I can see my buddy at 30+ feet = Excellent
The overall experience is improved if the buddy is wearing significant yellow or high visibility gear. A diver in all black is simply more tedious to keep track of.

Things (plants, critters, etc.) may not look nice / clear from any distance = Poor
Things (plants, critters, etc.) look nice / clear from 2 feet = Fair
Things (plants, critters, etc.) look nice / clear from 4 feet =Good
Things (plants, critters, etc.) look nice / clear from 8 feet = Very Good
Things (plants, critters, etc.) look nice / clear from 12+ feet = Excellent

Since distance underwater is deceptive I tend to estimate things in "diver lengths" using my buddy as a yardstick representing something like 7 feet with fins.

I'm perfectly happy to take anything beyond 30 feet as excellent as well. If there's nothing of interest in the first 30 feet go someplace more interesting.

Pete