2 quick questions

Hi guys,

My son is making the switch to the DIR philosohy and we have had some "spirited" discussion of the relative merits. I'm not a convert yet although I do see alot of the advantages. There are two quick questions that I would love to get informed answers to from the DIR community.

First, what is the drawback of a plastic tank protector. I can see that someone might not think they are necessary but why are they "forbidden" in the DIR configuration.

Secondly, why is a canister light mandatory as opposed to any other kind of reliable high powered light. Canister lights are INCREDIBILY expensive and I have seen some really powerful non-canister lights but my son tells me that a canister is the required light in a DIR configuration.

I'm just a crusty old trying to understand!

(1) What is a "plastic tank protector"?

(2) A can light is not required.

Those plastic mesh sleeves to protect the finish on the tank.

What purpose do you find these serve in the water?

Dhboner:

Those plastic mesh sleeves to protect the finish on the tank.

Click to expand...

I don't think anyone ever suggested that they were useful in the water but if the aren't a hazard in the water and they protect the tank from damage and possibly help it pass a few more visual inspections then why would they be "taboo".

If you like to play this one line baiting game could you move along and let someone more helpful step up.

It's not baiting, it's just getting you to try to think through this issue. If that doesn't sound like something you're interested in, DIR isn't for you.

If something isn't useful IN THE WATER, you don't take it for a DIR dive. If you want to protect the cylinders out of the water, go ahead, but consider removing them when you dive since there ARE potential hazards to their use. They certainly increase the chance of getting caught or entangled. That downside (a safety issue) rules them out for me over the possible upside (a potential cosmetic issue).

Personally, I don't use them. My cylinders all look great. No one I know has ever had an issue passing a VIP because of not using them. There are better ways of protecting your cylinders from damage that don't add any increased snag/entanglement possibilities.

Looking good takes a backseat to even minor safety issues in DIR.

Dhboner:

I don't think anyone ever suggested that they were useful in the water but if the aren't a hazard in the water and they protect the tank from damage and possibly help it pass a few more visual inspections then why would they be "taboo".

If you like to play this one line baiting game could you move along and let someone more helpful step up.

Click to expand...

Dhboner:

I don't think anyone ever suggested that they were useful in the water but if the aren't a hazard in the water and they protect the tank from damage and possibly help it pass a few more visual inspections then why would they be "taboo".

If you like to play this one line baiting game could you move along and let someone more helpful step up.

Click to expand...

Hey,

I think you'll find that the first question DIR followers ask is why use it. Chris wasn't being rude in asking. Basically if it's not needed, don't take it. I don't think you're going to have a DIR diver not dive with you because of the mesh sleeve on the tank, but realize it doesn't serve a purpose.

As for a can light, not needed. Do remember that the goodman handle is the best way to hold the light however. That way it leaves the hand free to do things without dropping the light.

Rainer:

It's not baiting, it's just getting you to try to think through this issue. If that doesn't sound like something you're interested in, DIR isn't for you.

If something isn't useful IN THE WATER, you don't take it for a DIR dive. If you want to protect the cylinders out of the water, go ahead, but consider removing them when you dive since there ARE potential hazards to their use. They certainly increase the chance of getting caught or entangled. That downside (a safety issue) rules them out for me over the possible upside (a potential cosmetic issue).

Personally, I don't use them. My cylinders all look great. No one I know has ever had an issue passing a VIP because of not using them. There are better ways of protecting your cylinders from damage that don't add any increased snag/entanglement possibilities.

Looking good takes a backseat to even minor safety issues in DIR.

Click to expand...

Now that's a very helpful answer. I'm a little long in the tooth for socratic teaching on the internet so I apologize for being short with you. Thanks.

In my experience, the sleeves make it a bit more likely that you won't get a good "set" of the cambands, and the tank will slip.

Every piece of equipment you use, in a DIR setup, has to be scrutinized for what advantage it brings to the dive, and what potential failures it creates. Keeping the finish on the tank attractive ranks way below a potential risk of having a loose tank at depth, so the mesh sleeves don't make the cut.

With respect to lights, several things are considered. Enough power for the task at hand (which can be quite different between a tropical reef night dive, and Puget Sound murk), at least double the expected burn time (keeps batteries alive much longer than burning them down to exhausted on a frequent basis), minimal failure points (thus an avoidance of switches where possible), and the ability to keep both of the diver's hands free for any necessary tasks (like buoyancy control, ear clearing, and later running a scooter or line).

For open water night diving, there are some lights now that meet all of those criteria and are capable of being carried on the back of the hand in a light sock or Goodman handle. In those cases, one wouldn't need a canister. The existence of the canister is to meet the burn time requirements for lights, in circumstances where a lot of power is required (low viz, caves).

It is really a very thoughtful system, and despite what you may find on the internet, there are a lot of things that are not set in stone, but are dependent on the dive at hand, as this photograph from Bob Sherwood's Cayman Quest trip demonstrates:

Quick Disclaimer: I am not a DIR diver, however I do subscribe to most of their practices. I dive sidemount, which isn't allowed, and also do photography, which also isn't allowed. I still use the minimalist approach for most applications and all that other stuff. It just makes sense...

Other problems with the sleeves is if you aren't careful and don't get the rinsed properly after ocean dives they can actually cause more VIP problems than not, causing surface rust and pitting.
I have 4 PST bottles that are over 20 yrs old, they still look fine. Some chips on the galvanizing, but that's it. No crazy stickers, just VIP and Nitrox, and that's it.

The can lights aren't required. The pistol grip lights are not allowed. They restrict use of that hand. Big Big problem when running lines especially. The Goodman handle allows for full use of that hand while still having use of the light. The pistols are also really spread, which is great for reef diving *doesn't scare away any fish*, but really bad for caves *can't signal with them*