Comfort Level in Crappy (very low to no) Vis

[Squirrel Girl]

Some how I think your zen place is determining if that silt out is composed of particles that are 0.0039mm or 0.0625mm

LOL! I'm still chuckling as I type this! Har, har, har!

[FW]

FWIW, "zero viz" is exactly that, ZERO! Some people call 2' zero. If you can see the line in your hand, that isn't zero. True zero viz is when you can't even see the glow from a 24w HID a foot away. I have seen it so bad that you can barely see the glow of a HID when it is about to touch your mask.

[Squirrel Girl]

FWIW, "zero viz" is exactly that, ZERO! Some people call 2' zero. If you can see the line in your hand, that isn't zero. True zero viz is when you can't even see the glow from a 24w HID a foot away. I have seen it so bad that you can barely see the glow of a HID when it is about to touch your mask.

I've hardly ever been in true zero viz. This summer in the travertine springs, I had about 1'. It was pretty crappy, but if I held my sampling materials close to my face, I could see them. Only once during my dives did I start to get a little anxious, but I was able to just "stay calm" and it was fine.

[Greenwood_60]

Can we define "low" vis? On the line, but can see it? Can see your arm but not your hand? Can see the glow of your light, but effectively nothing else? Some people consider <30' low.

Zero vis doesn't bother me. The thought of returning through new-to-me restrictions in zero vis shortens my dives. I won't pass through two new-to-me zero vis restrictions in one dive. Not confident enough yet.

[Squirrel Girl]

Can we define "low" vis? On the line, but can see it? Can see your arm but not your hand? Can see the glow of your light, but effectively nothing else? Some people consider <30' low.

Zero vis doesn't bother me. The thought of returning through new-to-me restrictions in zero vis shortens my dives. I won't pass through two new-to-me zero vis restrictions in one dive. Not confident enough yet.

I'm not sure we can define low vis. It means different things to different people, as you say. Plus, it depends on whether it's silt, tannic water, percolation, etc.

I noticed this summer that I could see my hands at arm's length because they were so pale. My black drysuit faded into the murk fairly quickly, but then I could see my hands because they were "bright."

There's also the difference between how far you can see when you shine your light versus how far away you can see someone else's light.

What does it matter how far away you can see some barely faint glow versus actually see an object. I'm sure for many people, seeing a glow is more comforting than seeing NOTHING. But what does that really mean?

[FW]

Can we define "low" vis? On the line, but can see it? Can see your arm but not your hand? Can see the glow of your light, but effectively nothing else? Some people consider <30' low.

Zero vis doesn't bother me. The thought of returning through new-to-me restrictions in zero vis shortens my dives. I won't pass through two new-to-me zero vis restrictions in one dive. Not confident enough yet.

Too many variables. Mostly depends on the experience of the individual. If I can see both walls of the cave, I consider that good. However, that could be anything from 3' to 50', depending on the size of the passage. To me "low viz" is when I have to stay close to the line, but not actually touch it. Even that distance varies, due to silt, and/or presence of something/someone that might make it worse without warning. Anything under 2', and I am holding the line, but anything over 1' I don't have to feel around a tieoff, so I am still quite happy. I don't care for zero, especially in a tight restriction. Too much danger of not getting my body in the right position the get back through it.

I agree 100%, I always turn early if I know I have to negotiate a restriction in low visibility.

[Squirrel Girl]

I agree 100%, I always turn early if I know I have to negotiate a restriction in low visibility.

So, I can't say I've done a lot of this, so this is all a mental exercise. But it kind of depends on what a restriction means. Yes, in general having done something before always makes me more comfortable. But if it's a restriction where it's not big enough for me to swim through with my buddy by my side yet still big enough that I am not struggling against the rock, I might actually be quite happy. If I drop the line, there's only so far I can be off track. I *don't* want to get entangled, though.

[FW]

So, I can't say I've done a lot of this, so this is all a mental exercise. But it kind of depends on what a restriction means. Yes, in general having done something before always makes me more comfortable. But if it's a restriction where it's not big enough for me to swim through with my buddy by my side yet still big enough that I am not struggling against the rock, I might actually be quite happy. If I drop the line, there's only so far I can be off track. I *don't* want to get entangled, though.

The "official" definition of restrictions:
Minor restriction, not big enough for buddies to swim side by side.
Major restriction, requires gear removal.

The latter is what I was referring to.

[Squirrel Girl]

The "official" definition of restrictions:
Minor restriction, not big enough for buddies to swim side by side.
Major restriction, requires gear removal.

The latter is what I was referring to.

You can have it!

[Greenwood_60]

I'm not sure we can define low vis.

Sorry, my question was rhetorical. I agree. Maybe we need a poll "At what point do you consider it 'low vis'?" I agree with Forrest, if I can't see both walls I consider it low. Doesn't bother me. I'm a little uneasy when I can't see either wall. My one dive in Lafayette Blue was about 5' going in, and 10' going out.

The "official" definition of restrictions:
Minor restriction, not big enough for buddies to swim side by side.
Major restriction, requires gear removal.

The latter is what I was referring to.

IMO, Minor restrictions are anything that doesn't require body or gear manipulation. Major if it requires wiggling, struggling, dumping your wing, moving tank or tanks. Actual removal of both tanks (all 4 points of attachment removed) makes it a No Mount restriction.