Doubles

[jonnythan]

I'll toss in that it's also much easier to use doubles on a boat than singles. No tank switching or anything.. easy easy. And you also get to use more of your gas.. no leaving 1200 psi in one tank and 1000 psi in another, which you then have to get filled. You've got enough for one more dive after that in dubs.

I do strictly rec diving, and while tech diving is in my future, I find the doubles much more convenient for what I do now.

 

[Diver0001]

Just because you have tons of gas on your back doesn't mean you are going to use it all in one single dive. It is all in what you are planning on doing.

I have to agree with this. Having big tanks doesn't magically turn people into idiots.

The question of "why" is still very relevant, however. Most people have this illusion that they can simply strap on a set of doubles and immediately be safer, which isn't true. Safety comes from more than your gear and even getting the full benefit of the redudancy of twins takes some practice.

R..

 

[Firediver]

Does anyone still use the Yoke to Yoke Manifold??? Just curious. I have one and was told it is still in great shape. It's a Sherwood and it's about 14yrs old... I use it only to balance tank pressures right now..... just curious.. should I wait and just save the money to buy a manifold and isolation valve????

 

[jonnythan]

should I wait and just save the money to buy a manifold and isolation valve????

Yes

 

[lamont]

The question of "why" is still very relevant, however. Most people have this illusion that they can simply strap on a set of doubles and immediately be safer, which isn't true. Safety comes from more than your gear and even getting the full benefit of the redudancy of twins takes some practice.

As a beginning doubles diver, I would have to say that you will, in fact, be immediately less safe than you were with singles. You've now added interesting failure modes due to user error like your isolator being closed, or your left post being closed.

 

[cool_hardware52]

As a beginning doubles diver, I would have to say that you will, in fact, be immediately less safe than you were with singles. You've now added interesting failure modes due to user error like your isolator being closed, or your left post being closed.

Good Points. Learn how to do valve drills......and practice regularly.


Tobin

 

[jonnythan]

Good Points. Learn how to do valve drills......and practice regularly.


Tobin

And take a few breaths off each regulator before you get in the water

 

[ianr33]

We went to Windy Point on lake Travis this morning and had a great dive.Max depth 125 feet,down in the old Pecan trees Run time 50 minutes using 30% nitrox. This was not a technical dive,less than 130,no deco,no overhead and I could have JUST done it on a single tank, but not IMHO safely. On dives like this I LIKE having doubles for the redundancy and for knowing that gas supply is not an issue.

 

[lamont]

And take a few breaths off each regulator before you get in the water

also, check your pressure gauge at a 10 min or 20 min mark to be sure your isolator isn't closed. if your isolater ever is closed, abort the dive and get on your buddies backgas because you no longer know what gas you are breathing. do a flow check (modified valve drill) before descending. do a flow check after every valve drill. if you do an s-drill both team members must be ready for a left post rolloff to become suddenly apparent. when you're doing valve drills, purge each reg before going to it. when doing valve drills, the other team member(s) must be ready to donate in case it goes south. you also must be watching the guy doing the valve drill attentively so that you are head of him and can stop him before he turns all his air off, or donate.

those are most of the issues that i've learned so far.

 

[jonnythan]

also, check your pressure gauge at a 10 min or 20 min mark to be sure your isolator isn't closed.

One of the things I've been taught is to do a flow check every 5 mins. Take a snapshot of your depth and time, check your SPG, and feather all your valves to make sure they're open. It helps to make sure everything is going according to plan and forces you to make sure everything is OK. Breaking the dive into 5 minute snapshots also helps with a lot of other things.