Just received the Fundamentals book

[JustJoe]

Any deco info is taught in later classes, not in the DIR-F. And it's not in the book.

Is it true then that all dives are considered deco dives by the GUE folks? If so, why not teach that stuff early?

Joe

 

[detroit diver]

Is it true then that all dives are considered deco dives by the GUE folks? If so, why not teach that stuff early?

Joe

I think most agencies consider all dives deco dives. Some just call it a safety stop.

As for teaching it early, my guess is that you need to learn the skills to handle deco stops before teaching what they are. That's what the DIR-F class is for. Once you learn the skills, the next step is decompression class.

 

[Soggy]

Is it true then that all dives are considered deco dives by the GUE folks? If so, why not teach that stuff early?

Joe

Yes. Every dive is a deco dive. There is no such thing as a No Decompression Limit. They are just deco dives that have the decompression built into the slow ascent. When staying within the "NDLs," we are taught to do a minimum deco ascent profile. Stops are considered mandatory but often don't mean more time in the water than a typical PADI profile. For example, an ascent from 100 ft would have me out of the water in 8 minutes, vs a PADI profile which would take around 6-8 mins. The difference is in GUE, we'd start doing deep stops at 80% of the max atmospheres (around 70ft on a 100ft dive) and stop every 10 ft for a min all the way to the surface.

All this being said, "NDL" diving is a whole lot less risky from a DCI perspective, and doesn't necessarily require all extra training that a dive requiring 45 mins of deco does. The chances of taking a hit after blowing off some "NDL" deco is very very low vs. spending 30 mins at 150 ft on 21/35 and requiring 30-45 mins of deco.

 

[JustJoe]

I think most agencies consider all dives deco dives. Some just call it a safety stop.

As for teaching it early, my guess is that you need to learn the skills to handle deco stops before teaching what they are. That's what the DIR-F class is for. Once you learn the skills, the next step is decompression class.

That makes sense. Thanks.

Joe

 

[MXGratefulDiver]

Hey DD,

I might have to go back and rethink my current gear and the rest of the DIR rig to fully get the magnitude of the problem. I dive exclusively in South Florida. Never been to a spring, only ocean or Gulf. I have a back inflate bc and usually a 3mm shorty (or a 3mm 1pc jumpsuit if it is winter). With a steel tank I still need 12 to 14lbs.

So I guess I would be overweighted in a bp/w? Sound right?

Joe

ps> I don't know if this matters but I have heard other people mention height and weight. I am 75" and 250.

Well, we're all a bit different, but it does sound like you're seriously overweighted.

For comparison, I'm six inches shorter than you and about the same weight (aka "fat"). On a recent trip to Bonaire, wearing a full-length 3 mm wetsuit, AL plate (-2 lbs), and AL80 cylinder, I was wearing 4 lbs on a weightbelt.

You didn't mention what type of BCD you are wearing, but some of them have a lot of padding that's buoyant. To find out if this is the case, take your BCD, nothing attached, deflate the bladder, and lay it in the water. Does it float? If so, put some weights in the pocket and see how much it takes to sink it. That'll give you an idea how much buoyancy your BCD is providing ... and how much you could shed by going to a BP/harness setup. You will be able to remove from your weightbelt the amount of lead it takes to sink your current setup plus the amount of negative buoyancy the backplate you purchase provides. A standard SS plate is typically -5 or -6 lbs, while a standard AL plate is typically -2 lbs.

... Bob (Grateful Diver)

 

[JustJoe]

Yes. Every dive is a deco dive. There is no such thing as a No Decompression Limit. They are just deco dives that have the decompression built into the slow ascent. When staying within the "NDLs," we are taught to do a minimum deco ascent profile. Stops are considered mandatory but often don't mean more time in the water than a typical PADI profile. For example, an ascent from 100 ft would have me out of the water in 8 minutes, vs a PADI profile which would take around 6-8 mins. The difference is in GUE, we'd start doing deep stops at 80% of the max atmospheres (around 70ft on a 100ft dive) and stop every 10 ft for a min all the way to the surface.

All this being said, "NDL" diving is a whole lot less risky from a DCI perspective, and doesn't necessarily require all extra training that a dive requiring 45 mins of deco does. The chances of taking a hit after blowing off some "NDL" deco is very very low vs. spending 30 mins at 150 ft on 21/35 and requiring 30-45 mins of deco.

This brings the need for excellent gas management to the forefront. Most OW REC divers (like me) are trained that when you get to a predetermined PSI, then you ascend at a relatively slow pace and do your safety stop. If you add time to that wouldn't you need to also add the amount of air consumption to the equation? And if your air consumption changed on the dive due to whatever reason, do you now have to recalculate your SAC to know when to start your ascent? Or do you build the dive based around a gas consumption safety margin (meaning it should take x cf of gas so I am going to have x+y cf of gas)?

Maybe these are stupid questions.

Joe

 

[MXGratefulDiver]

FredT here on the board also makes and sells bp's and they may already be rigged as well.

My FredT plate came with a harness kit that included everything you needed ... but it wasn't assembled.

FWIW - Fred uses quality webbing, but it's extremely stiff. If you go this route, I'd recommend you soak the webbing in a solution of fresh water and fabric softener for a day or two to loosen it up a bit ... makes the assembly go a little easier.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

Now my question. Where does one go to find a DIR experienced diver? They just don't hang out at the lds that I frequent, and I have only seen one guy diving a rig that looked DIR (maybe a HOG diver because he dove solo) off a boat. Does this mean that I need to go and hang out at the caves like a groupie (I hope not). Where do you find these mythical divers?

Joe

Consider finding a shop that promotes GUE training and establishing a relationship. Perhaps get on the shop's local mailing list.

If it's DIR you're interested in, beware of just assuming that because someone's wearing a backplate that they know anything about it. Many don't ... even some who claim they do.

My advice ... go to the source. At an LDS who offers the training you'll find the real deal ... and in my experience, you'll find people who are willing to mentor. One of the advantages of the DIR approach to diving is that it's easy to find people who are into doing dives simply for the sake of practicing skills.

... Bob (Grateful Diver)

 

[JustJoe]

Well, we're all a bit different, but it does sound like you're seriously overweighted.

For comparison, I'm six inches shorter than you and about the same weight (aka "fat"). On a recent trip to Bonaire, wearing a full-length 3 mm wetsuit, AL plate (-2 lbs), and AL80 cylinder, I was wearing 4 lbs on a weightbelt.

You didn't mention what type of BCD you are wearing, but some of them have a lot of padding that's buoyant. To find out if this is the case, take your BCD, nothing attached, deflate the bladder, and lay it in the water. Does it float? If so, put some weights in the pocket and see how much it takes to sink it. That'll give you an idea how much buoyancy your BCD is providing ... and how much you could shed by going to a BP/harness setup. You will be able to remove from your weightbelt the amount of lead it takes to sink your current setup plus the amount of negative buoyancy the backplate you purchase provides. A standard SS plate is typically -5 or -6 lbs, while a standard AL plate is typically -2 lbs.

... Bob (Grateful Diver)

I am beginning to believe that I am overweighted myself. I will be going to a lake next week for a search and recovery class and will take the extra time beforehand to get this taken care of one way or the other. It just feels so comfortable the way it is now.

I use a triple-l orion. I like the bc (couldn't beat the price) and I think that it has allowed me to dive more because of owning it (it has already paid itself off in rental fees that I saved). I knew from the get go that I wanted a bp/w but couldn't afford the price that the lds's around here were charging and didn't know anyone who could help me with the bp/w. It was a little daunting because I didn't want to spend the money buying the wrong stuff and then have unusable gear and still need to rent to dive.

I have some time to get the bp/w wing together and still dive, so I am going to start buying pieces and asking for x-mas goodies.


Joe

 

[MXGratefulDiver]

Joe ... keep an eye on ScubaBoard's Marketplace ... I got a great deal on an AL backplate recently. Someone also suggested eBay, which is another alternative.

Used backplates can be a good way to go ... it isn't like they wear out or anything. FredT sells a high-quality plate, as does Deep Sea Supply ... I own one of each ... but their price does reflect the quality of their product.

Your biggest expense will be the wing. Don't cheap out there. I personally like the Oxycheq ... and many just rave about Halcyon. Be careful not to purchase a doubles wing if your intent is to dive singles. And avoid wings that promote themselves as being suitable for both ... they are typically not optimal for either, due to the design compromises they have to make to accomodate both. Do some research down in the equipment section of this board ... in the Buoyancy Compensator forum ... there's a lot of good info down there that will help you out.

... Bob (Grateful Diver)