Tech 1 Cylinder Choices

[rjack321]

You're the 1st person I've known that's had a hard time with hp100s. Most everyone down here really loves 'em. I have 2 sets of AL80s in the garage from the Mrs. I've used them but they don't really work for me with a decent undergarment in salt water (need too much weight).

Rainer, how tall are you? Weight? That might have some bearing on what works well for you.

 

[Rainer]

I won't be using double 130s. Right now, I have a set of double LP85s, and will be doubling up some HP100s for a second set. Still deciding what to do with the AL80s (leave them doubled, break them down for stages/deco, or sell them). I'm moving to LA in July. How do the charters there work? Two T1 dives, one T1 dive then one rec dive, both? Here, it's usually one T1 dive per outing.

Edit: This is for GUE Tech 1.

Edit 2: Rjack, 6' about 165#. I trim out my LP85s nicely, so imagine HP100s should be fine. Not so concerned about *which* doubles to get (think I have that down), just how many, and what to do wrt AL cylinders (40s and 80s).

Thanks everyone who has posted so far!

 

[KMD]

you are getting lots of good advice from many people but ultimately what they have decided to do is only relevent to their diving they do and what logistical challenges they have.


Start with what you know and go from there.

You know that for your class you will need one set of doubles, one argon bottle and one 40cuft deco bottle.

Get these taken care of first and go take your class and dive a lot.

After that, decide on how many t1 dives you want to do and how often. Factor in the ease/hastle of getting fills and decide what gear fits in with with what you want to do..

 

[cmalinowski]

you are getting lots of good advice from many people but ultimately what they have decided to do is only relevent to their diving they do and what logistical challenges they have.


Start with what you know and go from there.

You know that for your class you will need one set of doubles, one argon bottle and one 40cuft deco bottle.

Get these taken care of first and go take your class and dive a lot.

After that, decide on how many t1 dives you want to do and how often. Factor in the ease/hastle of getting fills and decide what gear fits in with with what you want to do..

I think this may be the best advice of all. I have three sets of doubles (two "matched" sets and one AL80 set). I have one al40 and one al80 stage/deco bottle. I would probably like another al40 stage, but other than that, I don't find I have needed anything else at this point.

The tech1 dives are going to be, as stated already, about 160' for 30mins. That's one set of doubles and an AL40 for deco. If you are doing two dives and can't get a mix fill between the dives, bring both sets of doubles with mix and the al80 (I would bring the al40 too) just in case I needed it or something cause me to lose all/part the gas out of the other stage/deco bottle.

I don't see myself needing any additional double sets. If I was in cave country, I'd get two sets of 104's, but then I'd still only have the same # of sets as I wouldn't need thee 119's I have now.

I'd keep al40's and al80's as I could. They make great stage/deco bottles and continue to grow in usefulness as your diving does... at least that's my hope considering I'm only tech1 right now.

Just my thoughts...

Chris

 

[robzr]

I am only a lowly GUEf graduate, and I see the OP didn't ask what kind of doubles to get, just how many, but just in case anyone else is reading this I wanted to mention 2 quick points... I'm 6'0" I got x7-120s (long) and found they trimmed out perfectly for me, also 7.25" diameter is ~20% smaller front/rear surface area than 8" tanks, although the cD is probably low given the shape (I know nothing about fluid dynamics I could be way off here). Set of double x7-120s weighs 10 lbs more than x7-100s, but 10 lbs less than x8-130s, not incl. gas (ie good ratio of gas:weight).

Also, aren't larger tanks beneficial when doing penetrations, given that you may be diving only 1/3s or 1/6s. Again I'm just a peon hoping to take T1 in about 25 dives but this thread is good reading.

Rob

 

[JeffG]

I see the OP didn't ask what kind of doubles to get, just how many

Thats because it depends. Every "tech" trip I have done, we fill tanks in between dives, so only one set is needed.

Depending on the boat and the number of divers, it might be hard to get two complete sets of gear onto the boat.

That might lead someone into using stage bottles for bottom gas and trying not to use their backgas. Again...you could do 2 dives using two stages and your back gas...but if you confine yourself to "tech 1" blinders...then you wont be doing that. LOL

 

[MXGratefulDiver]

I think two sets are practical unless you have easy access to a fill station ... one set for your tech mix, and one set for recreational dives.

Keeping in mind that most people who go to Tech 1 are reasonably new at it (else they'd be working toward Tech 2), you're gonna probably want to be diving doubles all the time ... for "familiarity" reasons. Having two sets means you don't have to "waste" the leftover mix in your tech set on recreational dives, and start from scratch on your next tech fill.

I started out with two dissimilar sets ... E8 119's for tech diving and E7 100's for recreational diving. Loved the 100's ... but they dived a lot different than the 119's and I was constantly having to make adjustments when I swapped from one set to the other. So I got rid of the 100's and got a second set of 119's.

Whatever size tanks you settle on, I think it makes sense to get matching sets.

... Bob (Grateful Diver)

 

[limeyx]

You're the 1st person I've known that's had a hard time with hp100s. Most everyone down here really loves 'em.

I have exact same issue with 100's (and you know me
I have AL plate, tail weight and a belt and still I am hugely head down. it sucks.
With an extra vest I am just about OK.

5'6 and kind of porkier day by day in my case

 

[rjack321]

In the LA area you'll be on small boats for T1 dives (max 6 divers by and large). The bigger boats won't allow doubles, tech dives etc. So the optimal setup FOR THAT AREA seems to be: 1 set of doubles, an AL80 of backgas (or 32%), and 1 or 2 AL40s. This allows you to do 2 Tech1 dives or a Tech1 plus 2nd recreational dive.

Now getting fills is completely seperate from this. Given the timing and driving distances in the LA area you want at least 2 sets, sometimes 3 sets of doubles.

I would definately keep the AL80s. They may not get a ton of use, but they are invaluable when you need them, and a pain to try to rent.

 

[limeyx]

I won't be using double 130s. Right now, I have a set of double LP85s, and will be doubling up some HP100s for a second set. Still deciding what to do with the AL80s (leave them doubled, break them down for stages/deco, or sell them). I'm moving to LA in July. How do the charters there work? Two T1 dives, one T1 dive then one rec dive, both? Here, it's usually one T1 dive per outing.

Edit: This is for GUE Tech 1.

Edit 2: Rjack, 6' about 165#. I trim out my LP85s nicely, so imagine HP100s should be fine. Not so concerned about *which* doubles to get (think I have that down), just how many, and what to do wrt AL cylinders (40s and 80s).

Thanks everyone who has posted so far!

LA: 90% of boats are recreational only. Many of them are singles only.

Of the boats that will let you tech dive, you can usually bring whatever you want, but sometimes the 130's are best for the 6-packs as there is simply no room for 2 sets of doubles (so either 130's or an AL80 stage for one dive)

Sometimes we use an AL80 of 50% to save room too, but this is more bulk to drag around.

Most charters you can tech dive on are either 2 T1 dives only, or very occasionally 1 T1 followed by 1-2 recreational.

For beach diving usually singles is plenty, or a small set of doubles (LP80/85 or HP100) is more than enough.

One T1 per outing gets expensive at $175 + tip for the boat, but we may have access to more boats if we can reliably get more people signed up.

Get in contact when you get here and we can go dive -- my T1 buddy list is getting shorter not longer these days.