What's Wrong With This Mod-S drill?

[Bismark]

I do this before cave dives right before dropping down (but still underwater, right under the surface) or before quarry dives in 4ft of water (hovering, in trim) before skills dives.

Why? Because my wing is normally pumped up enough that it's difficult to get the long hose from under the light canister while I'm floating at the surface before a dive. Let a bunch of air out, enough so that my head won't stay above the surface, and I'm good to go for a mod-s.

Try leaving about 1 inch or so of slack before the buckle that holds your canister light and your canister light itself. (As opposed to your canister light held tight against your backplate) This allows the canister light to move forward slightly when your wing is inflated but does not affect anything else. You will be able to easily do a mod S drill on the surface and restow the hose with a full 40 or 60 pound wing.

 

[Bismark]

Sure that makes sense.

That last fundies class I hosted out here, the instructor had everyone doing them underwater with light in hand (as I recall). So it's the habit we're in. Not saying it isn't overkill, just that it's what we have been doing. Actually, I have gone along with my team on this one. Personally, I'd be ok with doing the mod s at the truck.

During the GUE EDGE, when we verify the light, we turn it on and deploy it, and it stays in the hand. It is deployed because (believe it or not) there has been the rare occasion when someone's light cord is trapped or something, and that needs to be addressed on the surface. Also, light in hand means light not shining in someone's face (yeah, you could flip it over and clip it - but we use that dangling position for only underwater when needing to clip off for a quick second. Otherwise we keep it tight). So the light is already in the hand when we get to the MOD S, if we're following GUE EDGE.

There is something about descending to 20' of blue water, forming a 3 man star and doing a Mod S before descending into the dive that centers you. When we are doing a 2-bottle deco dive with scooters, and we can all relax at 20', hold our position and everyone can see the easy deployment of the primary hose, it's like a moment of, "ok, here we go" that says we are all ready.

You are right, it may not be necessary, but just something we got into doing after the last fundies class. When divers are isolated in an area, and an instructor comes out, gives a class and leaves, you are not subject to the influence of other divers - good or bad. We may be too much by the book with some things, or have accidentally misinterpreted or slowly changed other things. Who knows? I don't have a problem with doing a MOD S at 20', if that's what my team wants to do. The truth is, when I have traveled and dived with DIR divers, they often do their own abbreviated version of GUE EDGE, including often skipping bubble checks.

It would be nice for some fundies instructors to chime in on doing the MOD S underwater with light in hand or not. Again this is not a big deal for me, just something to talk about. Truth is, until now I though most everyone did it underwater.

Hi Rick,

Interesting comments above about how things can slowly change over time and you adapt to the local conditions or how your team operates. I like the concept about "centering" yourselves before the larger dives. There is an interesting thread that Thalassamania is writing about the Scripps dive program where this "centering" aspect is practised before every dive session. Moreover, I would suggest also that this is the reason the GUE EDGE is actually done. Generally speaking, the gas planning, deco planning, etc is done prior to the GUE EDGE but the last check serves as a way to bring the whole team onto the same page as it were. Kind of like the huddle on the field(or the gym floor)right before the clock starts in the big game.

For what's worth, here are a couple of salient points provided to me concerning the GUE EDGE and Bubble check and Mod S drill by a GUE Training Council member (Instructor examiner) and a few GUE instructors. This is what is taught to Fundamentals students, Tech I students, and Tech II students by this IE.

1) complete GUE EDGE on surface. (light is switched on but left clipped off and tucked into waist band. The light will be pointing straight up at this point and not in someones face as you are vertical in the water)

2) The Mod S drill is done on the surface and includes full deployment of long hose verified by team members. (it is their gas after all.....)

I think the importance of doing the Mod S drill on the surface is partially because most often dive "drama" happens on the descent or ascent. I personally would like to know that if I or any of my team members have a problem in 5 or 20' of water our entire team is able to fully deploy the long hose. Also, sometimes in current or using an anchor line, we don't have the option of triangling up at 20'. At least this is the case for some of our conditions here. Of course, this begs the question of doing the full meal deal on the surface as well for the same reasons. What we do then is do our GUE EDGE etc. on the boat and do your bubble check on your descent.

Best,

Guy

 

[rainman_02]

The only thing I worry about with the new 20' stop on the descent is current and drop style (i.e. live boat).

I see the "stop at 20' and do a Mod-S" during Fundies as a buoyancy drill and nothing more. You should do your pre-dive checks in the most advantageous location: on the breakwater wall, in Whaler's Cove, on the boat, at the surface / anchor line when it is calm.

The best time I could see for a 20' descent stop would be with rough (10'+ swells) surface conditions and no current...the basic pre-dive brief should have been done before getting in the gear on the boat, the dive-site specific information is received, and a quick ok check on the surface...get out of the conditions and suss out the Mod-S, Valve, and Bubble checks in calm water.

Other than that...I see no problem with it, but you have to be mindful of conditions.

 

[SparticleBrane]

Try leaving about 1 inch or so of slack before the buckle that holds your canister light and your canister light itself. (As opposed to your canister light held tight against your backplate) This allows the canister light to move forward slightly when your wing is inflated but does not affect anything else. You will be able to easily do a mod S drill on the surface and restow the hose with a full 40 or 60 pound wing.

I do.

Both DSS Torus wings I have (38 and 49lb versions) tend to have a good squeeze going at the surface, especially with my 13.5ah battery canister. Once you're horizontal and in trim they're both fantastic, but floating the surface while pumped up they squeeze you.

 

[allenw1972]

A few observations and opinions:

1. I have experienced many trapped light cord issues that were caught and corrected when doing the Mod "S" with the light. I have seen light cord wrapped around the belt just after the cord grip on the lid down at the canister. The light can be tucked as normal, but once deployed, the cord is not long enough to dive normally. Tracing this light cord from the light head back to the canister cord grip is the final procedure item in the Mod "S" for our team. This makes sure it is properly configured and not trapped or trapping something else.

2. I don't want to open the light cord over or under the long hose debate, but by using the light during the Mod "S", you can insure the light cord is under the long hose for the dive. It would be debatable that it would be easier to trap the long hose with the light cord if a Mod "S" was not done with the light deployed.

3. Doing the Mod "S" with a light in shallow water while neutral and holding team positioning is HARD. Doing it quickly is even harder. Doing it with learning divers is nearly impossible. Might I venture say, this may be the reason most don't do it underwater?

4. It takes time... (see #3 above) which often cuts into your bottom time and gas. Most divers want to get with it once in the water. Understandable. I would take more time if each diver did it individually and in some sequence. It may not be DIR, but we often get to 20' deploy, look around, OK everyone, stow, then dive. Yep... all at once. Again, I am sure this is not DIR, but it makes the drill much quicker.

5. So... what is Mod "S" (#3) in the basic 5. Muscle memory for the real "S" drill? One would think if the intention was to do this on the surface, we would call it the Basic 4.

Coldsmoke, I don't think "surprise" S-Drills are DIR/GUE either. You may consider looking for some new dive buddies, with that said, I am pretty sure you would get me gas at any point in the dive - quickly. You SI is always fantastic.

 

[Bismark]

I do.

Both DSS Torus wings I have (38 and 49lb versions) tend to have a good squeeze going at the surface, especially with my 13.5ah battery canister. Once you're horizontal and in trim they're both fantastic, but floating the surface while pumped up they squeeze you.

Thats a pretty big battery so I can see that........I woudn't be surprised if your wings are also cut different than mine (AGIR or Halcyon) also. I guess you could always get a pistol grip light.........wait a minute...........(just kidding of course)

 

[Bismark]

A few observations and opinions:

5. So... what is Mod "S" (#3) in the basic 5. Muscle memory for the real "S" drill? One would think if the intention was to do this on the surface, we would call it the Basic 4.

Practising the Mod S in the basic five is intended to develop buoyancy skills with the Fundamentals diver while task loaded while also building the stepping stones for the complete S drill. It is not necessarily intended as something to be a "stand alone" drill done UW. Neither Tech I nor Tech II use this component of the basic five in their sylabus except as a one of the preparatory steps before beginning a dive. (along with the GUE EDGE, mod valve drill which includes all bottles if using multiple bottles and bubble check).

 

[rjack321]

I have caught many a trapped long hose or light cord with a MOD-S and so I'm not so keen on using this check as a "centering" exercise at 20ft. Cause after having to undo someone's harness to fix a stuck XYZ, I am not going to be relaxed for the upcoming big dive.

Since we don't have surf, we do them on the surface for most shore and boat dives. For "hot drops" in current we do them on the boat deck.

 

[Bismark]

I have caught many a trapped long hose or light cord with a MOD-S and so I'm not so keen on using this check as a "centering" exercise at 20ft. Cause after having to undo someone's harness to fix a stuck XYZ, I am not going to be relaxed for the upcoming big dive.

Since we don't have surf, we do them on the surface for most shore and boat dives. For "hot drops" in current we do them on the boat deck.

Same here.

"Hot drops"? Wow, you make your dives sound like Navy Seal exercises! When can I get on your boat? DUI makes a great waterproof bag for my M-4..........I can see some extra checks for our dives in my future "ammo, weapons......." I guess this would be in the equipment part of our GUE EDGE drill......This is going to be great........

 

[Bismark]

BTW Richard, is your RIB bulletproof? Just checking...............