Bad vis. How bad is too bad?

[Jim Lapenta]

Recently two threads were started in the A&I forums about 2 fatalities. One question that came up was regarding visibility. Particularly as it relates to training and/or buddy seperation. Personally since adopting the procedures I have for my own diving and when teaching there is really no vis save zero that is too bad for either. Proper buddy procedures will prevent seperation in nearly all condtions. Save some type of natural disaster. When practiced by buddies who have actually been trained in proper procedures and USE THEM AT ALL TIMES.

So that is my view. What is yours and I'm putting it in the form of a poll with feet of vis as a guide. Divers can answer what their idea is and why.

Instructors same thing but please add how you adjust for low vis.

Note that for those who use poor buddy procedures or don't know what they are you are either solo or should still be in the pool regardless of vis!

 

[pnw_diver]

I said 2-4 feet - those conditions are not that uncommon in the PNW. I could dive in less, but prefer not to. Anything less than 8-10 feet or so isn't a lot of fun in my book.

 

[oldnotdead]

I did OW dives in 0-2ft vis. This was good for training, bad for dives of choice (mine). Also a few hundred yards and less than 3 mos from a Great White fatality. OND

 

[vondo]

The question that came up, IIRC, is what is the minimum viz that OW certification should take place in, not what is the minimum viz you would dive in.

I'm going to say 4-6 is "too bad" since 6 feet seems to me to be a minimum required for the student and instructor to see each other demonstrate the necessary skills for the OW certification.

 

[fdog]

For just fun diving, I will go ride a bike, or jump out of an airplane, rather than endure vis of less than 10 feet - it's just too much work.

For OW classes, 20 feet of vis is my minimum - I usually have OW student class sizes of 4 or 6, and I will not have them out of my sight. It's anal I know, but, I do not rely on students being in the sight of a DM (and out of my own vision).


All the best, James

 

[TMHeimer]

If I'm 2 inches from the bottom and can't see it, I go to a different depth/place. And if there's surge, Whoa. Time to get out of Dodge.

 

[ScubaSteve]

The question that came up, IIRC, is what is the minimum viz that OW certification should take place in, not what is the minimum viz you would dive in.

Agreed. This came up in reference to training. IMO the safe distance is dependent on the number of involved "support divers" (as in DM's or other instructors) along with the number of students. The more students, the bigger the "aea/distance required for skills, therefore a higher staff to student taro is required. IMO, less than ~5' bid = 1:2 ratio for safety.

 

[String]

It's too subjective. Here if the vis drops to 3m id class it as awful. In the UK if the vis is 3m id class it as a good day so it depends entirely on the normal conditions for the area.

To adjust for low vis you do things like reduce the ratios and so on. For example in the UK on entry level courses its rare i ever go in at more than 1:1 whereas here im happy with 4 or more depending.

A lot depends on the students and course being taught too.

In the real world you never have assistants to help so you're on your own so ratios and dives are dictated by how many you feel you can see or control at once. In low vis that might very well be 1 person.

 

[Dive Right In Scuba]

I think as long as you can see the student, to verify they can do the skills, there is nothing wrong with conducting class in Low viz.

Now, does that mean that is optimal? Nope....OW is not just about doing skills. Too many instructors think it is. It is meant to actually get out and dive....by doing a tour after the skills. 2 feet is not always best for this, but actually not too bad. Now, for us here, 2 feet is not that common. If you are on a platform, or near, you may have 2-5ft. But any instructor who knows the quarry can find some clear patches to do a tour. It may not be 50ft, but you can get better viz for a tour with a little local knowledge .

That being said, one Instructor should not have 5 students in such viz. DMs are extremely helpful. We always have at least one DM per Instructor. In times of horrible viz, 2 or more for extra eyes and safety (depending on how many students that Instructor has). Ratios do come down though with lower viz

An Instructor can not watch everyone while doing skills, and can not lead a tour while watching everyone even in optimal conditions. They can check on people in optimal conditions by turning around...but having a DM follow the pack is 100% better.

There is nothing wrong with doing training in poor viz. As Jim said, the Instructor needs to follow and teach certain criteria for those bad conditions when the arise. Most important that is HIGHLY stressed here is look for 1 minute and Surface. If something catastrophic does happen (while separated) at least you figured it out ASAP instead of 10+minutes later.

Although some people may criticize us Low Viz Divers, this is how we do it, this is what we have, this is what we train in, this is what WE LOVE, this is what our students LOVE.

Nothing beats good training and continued training. We give our students 1 month free rental after OW cert to come out and dive more with us or on their own to help solidify what they learned.....some utilize it, most don't.

 

[Pearldiver07]

If I can't be between 2 divers and see them both, it's not good enough to teach (unless we go to 1-on-1!!).

I usually keep the rule of # of students is less than or equal to # of supervising hands (and that's "Hands", not "supervisors").

I can keep them safe, but my main concern in low viz is then how the student is going to perceive diving after this.

Not a great sales card for diving. I always encourage a quick trip to Coz to see how nice it can be.