Help me with Low Visibility Ideas for classes

[malvarez2]

I'm working on my PADI DM now, and have assisted in a number of OW classes where the visibility is really bad (<5'). Usually these classes are 4-6 students with an instructor and 1 or 2 DMs. As part of our training (there are two DMC's in this class) my instructor has asked that we come up with some thoughts on making the OW classes better for the students, and minimize the need to surface to find lost divers. Below is a compilation of thought I have on this based on my experiences. Probably not anything new to most of you, but I would love to hear your thoughts and ideas on this. (Moving to another location with better vis is not an acceptable answer!)

The real goals here are to make the class flow smoothly, and keep the students calm and together while swimming in very low visibility. Thanks.

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Low Visibility Student and Buddy Tracking Thoughts

Tracking students in an unconfined low-visibility environment can be challenging. Problems with separation beyond the visible distance can cause confusion and anxiety at best, and time delays, re-surfacing or lost divers in the worst cases. This paper attempts to compile some steps that could be taken to reduce problems associated with this issues. It is specifically meant for open water classes where the instructor may be assisted by other dive masters.

Most of the classes that I have attended, or assisted have been in a lake where the visibility ranges from 15 feet on a clear day, to less than 5 feet on a day with a lot of other classes and water movement. This visibility is usually constant from the surface to, and between, the platforms that are used for the classes. To complicate matters, there are often multiple classes on the platforms or swimming between them. One major challenge is to keep your class from getting mixed with another class during an exploratory swim.
I’ll separate the thoughts into two parts. First, the dive planning, and second the dive itself.

Dive Planning:

• Describe to the students each step of the dive.​

o Buddy pair and DM assignments are made, and stress that the assigned group must stay together.​

o We will descend (Holding line, watching line, no line) and meet on the platform below. We will all wait at the platform until everyone is there.​

o Describe how to find the platform if you miss it on descent (at 33’ deep exactly, current probably pulled you south, so go north first).​

o We will do various tasks (describe each task)​

o We will then do an exploratory swim with the following dive buddy pairs and order of pairs.​

o Describe start and end of swim, and method of navigation. For OW classes, we often string a large rope between platforms to allow the class to follow for this swim. Otherwise, depth and compass headings should be discussed.​

o We will surface after everyone reaches the end point.​

• Describe lost buddy procedure.​

o If you get lost, you should search for 1 minute. If still unable to find group, do a normal ascent and wait for instructor or DM at surface.​

o While searching, listen for noise makers. They can’t give direction, but as you move you can tell if you are getting warmer.​

• Review notable scuba gear on each diver.​

o The instructor has yellow fins.​

o Your buddy has a green bathing suit.​

o Optionally, attach a colorful strap or marker to each student’s tank, and each instructor or DM’s tank. Maybe put 2 on the Instructor and DM’s to make them distinguishable.​

The Dive:

• Instructors and DM’s must be sure to keep buddy pairs together. If one is descending faster than the other, stop them and move them back to their buddy. Often students are too focused on equalizing, and descending to remember about their buddy.​

• Once at the platform, keep the students at the same level (i.e. holding the bar or kneeling together). 5’ visibility allows a DM to see only 3-4 students at a time if they are together.​

Missing Diver(s):

We rely on our five senses for everything. Underwater, taste and smell don’t do much good for locating others. If we could see them, then they aren’t missing. Touch is useful if there were a buddy line in place, but this is usually not the case for classes. This leaves sound. To help locate a missing diver, all instructors and DMs should carry noise makers of some sort, and agree on a set of signals such as:

• One pulse (shake or blurt) – I can’t see you, and I am sitting still waiting on you.​

• Two pulses – I can’t see you, and I am actively searching for you. This could also be a response to hearing a single pulse.​

• Three pulses – I can’t see you, and I am doing a normal ascent now.​

These noises could be repeated every 10 seconds, and after the 6th repeat, if no response is received or the party located, the diver should surface.

 

[ligersandtions]

It might not be feasible, but in conditions like that, divers really should be diving with powerful lights that can cut through the muck and make it easier for others to know their locations. I know buying lights for an OW class would probably be expensive....not to mention that in an OW class, students may feel task loaded when adding a light to their rig....but having a powerful, focused beam is really the best way I've found to keep a group together.

Another suggestion is not having as many students in the water at a time when the conditions are bad. The absolute worst thing (which you didn't mention when you were saying the best/worst cases) would be a student getting lost, panicking, and bolting for the surface while holding their breath....if the instructor and DM had only two students to keep track of, the likeliness of a situation getting to that point is greatly reduced. It seems, to me at least, that it would be better to do more dives in a day (as an instructor or DM) than it would be to take 6+ students down at one time and hope for the best.

 

[Jim Lapenta]

I really like that you stress proper buddy procedures. Keeping the pairs together at all times and in proper position is critical. None of this single file follow me bullcrap. The light suggestion is good also and with properly trained divers should not add to the task loading. In correct position it should require no more than a slight turn of the head to know where your buddy is. Adding a light just gives an additional reference. Marker lights on tanks are useful as well but should never be substituted for correct positioning. I like your outline overall and may actually use some of your tips should conditions warrant. Thanks for the post. Well thought out and well written.

 

[malvarez2]

I will add something about lights to my final version. Perhaps the DM's should carry them to use for direction and guiding. I also need to add something about limiting the student/DM ratio as mentioned.

I never though single file was a good idea. You need to know at least someone else is close without stopping to look behind you if you loss the guy in front.

 

[scubadiver888]

This topic will become important to me shortly. Our first open water session was cancelled but I realized this sort of thing could be an issue for us. There are dozens of clubs which all use the same location for OW training. It is not uncommon for a dozen clubs to be there. Visibility is typically 15' on a good day but once the students hit the water it quickly drops to < 5'. With 4 to 6 students each we are looking at 50 to 70 students in the water at once, not including people doing other things like Rescue Diver training.

I don't have a regular buddy I go diving with. For night dives I have small strobe lights I can attach to our cylinders. I have a pair of red, green and yellow lights. I believe you can get them in even more colours. What about using pairs of lights. One buddy team would both have red lights, next buddy team would have green lights, etc.

This would make it easy for buddies to find each other. Hopefully no one else at the site thinks to do this as well.

 

[Pearldiver07]

Having about 550 dives in Lake Travis teaching, let me throw in my 2 cents from personal experience.

First, if an instructor has DM's I strongly suggest that students not wait at the platform. I always kept my DMs on tour with students when they weren't being evaluated. More diving = more practice.

How?

Well, descend with divers and meet at the platform. The instructor should have already mapped out the timing, but I'd give each DM team a time interval to take the students out diving after we confirmed that all equipment is working and that their buoyancy is good.

Say, if I had 2 DMs and 6 students, then I'd tell DM 1 to bring his team back to me around 12 minutes into the dive. When he arrived, he's take the team I just finished with and take them out diving. Then I have DM 2 and team return to the platform at 24 minutes into the dive. At this point, I'd swap his students to begin evaluation, and he'd take the students I just finished up with out for more diving.

As soon as I completed my last set of skills, I take that last group out for more diving.

My goal, to ensure that students are never waiting around any more than necessary under water. That's not diving, it's just standing around breathing air under water.

There are a lot of variations on this. When I knew my DMs well, they'd bring students after I started, to meet me on the platform and perform the same swap. If there was an AI in the group, I asked him/her to conduct surface skills, then hand off students to the DM, and the process would continue from there.

In this way, students aren't wasting dive time waiting, and there's never a large group to manage.

For personal visibility, there are some very good cheap strobes out there to attach to the cam band. It allows students another 5 feet of so of being able to keep track of you. By being on the cam band it doesn't keep annoying you with the flashing.

On very bad days, I used to attach matching chem-lites to the teams (one team yellow, one team green, etc.) to make it easier to identify them. This was usually when viz was less than 2 feet though.

I did use a universal signal for my divemasters that if they heard repeated signals of 3 bangs to all surface with their students. This usually involved a false start where we couldn't get our collective selves together, but one time it helped because of student match ups getting confused at the platform.

Well, that's my 2 psi. If you have any other questions about Lake Travis teaching - shoot me a PM.

Have fun.

 

[ligersandtions]

In my (limited) experience using a chem light/stick, they don't put out a ton of light and aren't very helpful. In good visibility (like tropical night diving), they can be helpful as you can see who your buddy is based on the color of light hanging off the tank....but in bad visibility, the light is just not strong enough to cut through and be visible (that is, unless you are right next to your buddy).

An HID or LED light is preferable over a halogen light, imo. I know they are expensive, but if you (or your students) plan to dive in low visibility regularly, it is a valuable piece of gear....would not dive without mine!

 

[Blackwood]

Touch contact works pretty well.

Did some working dives last weekend removing nets; as soon as we touched them it was instant zero viz (well, not zero, I could see the blue of my drygloves and the orange of my buddy's z-knife, but I could not read my gauges). Remained in touch contact using touch hand signals in order to communicate.

 

[WVDiver]

These conditions are pretty normal for most lakes. We don't seem to have that many problems for the most part. I would suggest several things, link the platforms and entry to platforms with a permanent line system. The best material I have found for this is the white plastic coated nylon clothes line. It is cheap, lasts a long time and stays white forever even in dirty water.

Tanks lights for all students with Instructors and DM lights being all the same color but a different color from the students.

OW students in low vis have a lot of task loading going on and although buddy separation protocols are good to stress the reality is that most students won't remember it and lots of students have ear and sinus issues that may not allow too many ups and downs, especially in chilly water. Try to keep them down if possible. Sharp DMs paying close attention should be able to handle most of these issues.

Students with lights is not a bad idea but again consider task loading. Naturally the instructs and DMs should know where they are going. Sounds as though you have plenty to go around. Assigning students to instructs is a standard thing in most classes I have worked. Having all the students arrive at the platform at the same time is not necessary as long as they are with an instruct. Spacing small groups one minute a part with a known meeting place works well as only one student usually does skills at a time anyway. Keeps the waiting down for them and helps them relax.

Although single file may not be the ideal situation it does work for traveling to and from platforms with students. Putting an Instruc/DM in front behind and between buddy teams works well and once on the platform skills can be performed.

For OW student dives where skills from the platforms are not the primary objective and tooling around to work on buoyancy and get the feel of the dive site is more your task it works well to take one or two buddy groups together with an Instruct/DM in front and behind. Should a student ascend to the surface the instruct and other students stay while one instruct retrieves surfaced diver.

Also diving within view of the bottom so that you always have a visual reference will help keep the students from bolting to the surface. Confussion sets in quick when they can't see a solid object even when they can see you. I know this has its own set of problematic issues such as silting out and the like. A lot of lakes have some current to help with clearing, if your does utilize it.

There is no sin in teaching some frog kick techniques during pool sessions when you know the dive conditions for OW cert dives are problematic due to silt and vis problems. This will help a lot with the silt problem. DMs and instructs using scissor kicks are just as bad as students.

Lastly we split groups up and make them smaller, down to a single buddy team, if we have students that we know are likely to have issues with low vis, claustrophobic problems etc. The rest of the group can wait at the descent line and do surface skills, duff and don bc, pull out and replace weight pouches etc, while awaiting the down buddy team to surface. Then they take their turn.

 

[DevonDiver]

I'm working on my PADI DM now, and have assisted in a number of OW classes where the visibility is really bad (<5'). Usually these classes are 4-6 students with an instructor and 1 or 2 DMs. minimize the need to surface to find lost divers. [QUOTE}

If a problem happens, it needs to be fixed. If that problem happens to be a lack of effective in-water control, by an instructor over students, then it has to be fixed first time.

The obvious answer...when viz conditions make it impossible for an instructor to maintain control over a big group.... is to reduce the size of the group.

Having said that.... when I dove and trained in the UK, we often (normally) experienced viz conditions in the <5' range. The solution for us was effective planning and communication between the instructor and DMs.