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Discussion Starter #1
Im starting adv nitrox in a couple of weeks, and will be progressing onto side slung cylinders. Which is better 7 ltr ally or steel and why? Also who does good deals and has them in stock or even 2nd hand for sale.

thanks in advance

Gareth
 

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For some bizarre reason....
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Gareth,

The best advice I can give is to try both, and see which you prefer. Your course instructor should be able to provide some for the course, if not then I advise you try and borrow or hire some.

The choice is largely personnal, I prefer Ali. Out of the water ali is probably heavier and certainly bulkier than steel, but in the water I just don't notice them at all.

As to where to buy...... Godive always seem to have good prices, but Caveat emptor - check delivery (start of the season etc), and check when they were made (often cheap stock has limited life left before test required).

Cheers, Paul
 

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Discussion Starter #4
Cheers,

I was thinking along those lines to, he is bringing both ally and steel stages. So will see which i prefer, i was wondering the pro's and con's of both, but im guessing its down to personnal preferance.
 

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Guru
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I assume you're going to be using a single sideslung cylinder for decompression diving and that you're doing an Advanced Nitrox & Deco Course.

If that's the case then I would recommend an AL80 as your first cylinder.

Several reasons for this:

Lets assume you're doing 35-40m dives for about 35-40 minutes using 50% as a deco gas. You'll switch to 50% at 21m and for dives like this do about 30 mins deco. To start off with until you get comfortable - your deco breathing rate is going to be on the high side - say around 20 l/m at the surface. For deco from 21m up - you'll have an average depth of around c:10m which means you'll be breathing something like 40 l/m corrected for depth?

30 minutes of 40 l/m is going to use 1200l of deco gas. A 7l steel or 7l Ali will contain around 1500l of gas when full so you only leave yourself a margin of 300l for FUBAR type moments. I think the TDI/IANTD current recommendation is to take double the deco gas you need. GUE the agency I've trained with recommend 1.5x. By either standard you've not got enough gas.

An AL80 contains around 2200l of gas which is plenty for what you'll need - has excellent buoyancy characteristics and when you're not deco diving - you can fill it with the same gas you've got in your twinset and use it to get two really good dives by breathing it down first on the second dive of the day and then switching back to your twinset for the last part of the dive and the ascent.

Modern ALi7's are very heavy compared to older ones and they have broadly similar buoyancy charcteristics to a Steel7 - so there's no advantage either one way or the other.

HTH
 
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Utrinque Paratus
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which on eh?

well this is what you do you go out and buy the Ali 40 (5.5 Ltrs) and do the course with that because its small and you can handle it easy not to mention the cock ups arnt as bad as it's a small cylinder.

After the Pass you tell your better half that it is a bit small for the diving you are doing and if she wants you to be safe and well you need an Ali 80 (11.1 Ltrs) play with that until your happy with it and confident to take it off and on etc than you hit her with "Actually dear that cylinders is OK for when i get better but that Ali 40 is still to small i wonder if there is an Ali 7 out there i could get" thats a good idea "just so happens i have this number bingo you now have

Ali 80, Ali 7 and Ali 40 :D

leave it a few months and then start the process again telling her that your now diving with two stages :)

works better if your wife has blonde hair as the IQ drops by the minute :D

Graham
 

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Discussion Starter #9
Or even better when you dont have a wife!!!!!!!!!!!!!!!!!!!
 

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Utrinque Paratus
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Or even better when you dont have a wife!!!!!!!!!!!!!!!!!!!
you need to get one their great for

washing kit
dinner
washing clothes
etc etc :D

Graham
 

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Now a Silent Warrior
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WIFE =
W= Washing
I = Ironing
F = FU**ing
E = Every thing Else
 

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Hi Gareth

Take a look at some pictures of a 'new' al7 and steel 7 at various pressures: Index of /~andy/diving/al7

Can you guess which well dived Scottish site these photos were taken at? :)

Cheers
andy (formerly from Falkirk, now Oxford, and used to go to school at Chryston High :))
 

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Discussion Starter #14
Chryston high is just round the corner from me. I grew up in Thame not so far from Abingdon.

At a guess I'd say loch long possibly finnart or other side pass arrocher. looking at the muddy bottom with dead mussels on it.
 

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A prize to that man! Finnart is the correct answer, well done.

I miss the diving up there so much :( Finnart beats Stoney hands down any day! Hoping to get out with the club over Easter though.

andy
 

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Discussion Starter #16
Well if you ever want a weekend give us a shout.
 

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I've been looking for a 7l steel and the best prices for cylinders that I have ever received have been from Untitled Document. Up until 2 weeks ago they were £90 for a 7l Faber. I think they've now sold out as I can only see Beaver cylinders and they are £104 for 02 cleaned.

Failing that see if you can find Ivon as he is selling one 2nd hand I'd have gone for but unfortunately due to the transportation costs we couldn't agree a price.
 

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aka Chimp 1 or Mavis...
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Fiona, Only you can answer that based on your diving requirements. A 7l is probably fine if you are going to use 80% as the avg depth/DCR will be less but if you are using 50% then you might be limiting your bottom time due to deco gas requirements.

HTH
 
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