Can't take the cold anymore...

[trucker girl]

I think it's usually measured by wild-assed guess.

That's certainly MY prefered method! I'm really good at it, too!

 

[dave4868]

I agree, and I suppose as divers we can decide what vis (horizontal or vertical) is most useful to us. We can easily use our computers to see how deep we can go and still see the surface. To accurately determine horizontal vis at a given depth we would need pre-measured line, tape measure, etc.

I figured for our purposes we can use a simple (and easily reproduced) method to provide each other with an idea of how far we could see. In the particular example above, it is very rare in my experience to be able to see the surface from 50' of depth at Cat. As soon as we hit the water and looked down we knew we had a great chance for some great vis. It was just very clear compared to what we usually see. Sometimes on a free ascent we can't see the surface from our safety stop depth of 15 or 20'.

I wonder what kind of vis we'll have this weekend....

--Matt

Hmmm.... stiff west winds all week are predicted. That should clear things up even more!

As soon as the air temps moderate a bit, I'll be at Front Beach, Rockport!

It's got to be a halfway comfortable surface interval for me, since I like to do more than one dive (and I'm old and hate to be cold!).

It's kind of nice to get good vis and actually be able to back up the claim later, so my flag line is marked every ten feet, making it easy to measure horizontal vis.

Best I ever measured around Cape Ann was 75' at Front Beach. Late spring, I think it was.

I was glad I was able to measure it because I wouldn't have believed it myself otherwise. Saw squid in the middle of that day, too. A very special day.

Can't wait to get back into the water. It's been 3 weeks and I'm in withdrawal!

Dave C

 

[JohnL]

I usually check the vis to the surface and then also attempt to guesstimate linear distance (which seems to often be less). We did two dives at Folly on Saturday, and I'd estimate the vis at 25-30' (a bit better on the left side of the cove than the right). Could make out the surface from 30'. Did two 50 minute dives, with water temps at 39F. Is motivation to try to get my dry gloves working before the ice diving class next weekend.

Hmm...was there too on Saturday. Best vis I have seen locally. We hit 60 feet on the right hand side and it was still pretty bright. Only did one dive due to a minor suit leak.

 

[paulthenurse]

John, did you get your seal fixed? Want to go on Monday or Tuesday?

Oh, wait, I'll be in Key Largo!


(Sorry, I couldn't resist.)

PTN

 

[MSilvia]

I figured for our purposes we can use a simple (and easily reproduced) method to provide each other with an idea of how far we could see.

Absolutely, even if the vertical visibility isn't the same as horizontal vis, I'd be willing to bet they're strongly correlated, and in any case good vertical vis usually means better ambient light penetration. Since it's an easy number to get, I think it's at least useful for comparative purposes.

I wonder what kind of vis we'll have this weekend....

I'm hoping it'll be great at Hathaways... once we saw a big enough hole to dive through!

 

[johnnyseko]

John, did you get your seal fixed? Want to go on Monday or Tuesday?

Oh, wait, I'll be in Key Largo!


(Sorry, I couldn't resist.)

PTN

I'd be up for Monday or Tuesday...

...oh darn, I'll be in Costa Rica! (had to join in the fun)


As for judging vis, I usually take a guestimate based on how far ahead of me I can make out an object or other diver.