Info Scootering and RMV

[stuartv]

I did 6 dives over this past weekend. All in the same configuration (double steel 120s, 5mm wetsuit).

5 of the dives, I was working with a student. The 6th dive (actually, dive #4 - last dive on Saturday) I got in by myself and did a 45 minute run driving my BlackTip scooter.

I downloaded all my dives and happened to look at my gas consumption data.

For the 5 dives not scootering, my RMV ranged from 0.58 to 0.63, with an average of 0.61 cubic feet per minute. Very consistent. Surprising, to me, really, considering some dives I swam a short way and then mostly just hovered next to a platform, but other dives I was swimming (fairly slowly) the whole time.

On the 1 dive scootering, my RMV was 0.36. LOL! Went from 1246psi to 860 in 45 minutes, with an average depth of 23 feet.

Awesome how much scootering helps extend my gas!

 

[scubadada]

Hi Stuart,

What a surprise, no work, no gas consumption.

I just finished 2 weeks in Bonaire, probably the easiest diving I do. My average RMV over 1,600 dives is 0.36 cu ft/min, on this trip, over 45 dives, just 0.32 cu ft/min. I had my lowest RMV ever, at 67 years old, 0.26 cu ft/min.

 

[stuartv]

@scubadada That is awesome! I WISH I had numbers even close to that!

That scooter dive was my lowest recorded RMV ever. But, now that I think about it, I don't use AI transmitters on my deco cylinders, so I don't record their start and end pressures like I do with back gas. I *suppose* my RMV might normally be around that when hanging on deco, but I don't know. Somehow, I doubt it. Otherwise, I've been at around 0.43 or so, when doing a drift dive in Cozumel.

0.36 is encouraging to me because I didn't know I was even capable of doing that comfortably.

 

[happy-diver]

I go beserk playing battle with my scooter in the ocean

So my sac goes up, way way up

 

[johndiver999]

yeah a scooter is a good way to get bent if you are not paying attention and have acclimated to just looking at your gas supply.

 

[happy-diver]

I don't see how someone that is overly attentive with their spg would not pay attention to depth

 

[stuartv]

I don't see how someone that is overly attentive with their spg would not pay attention to depth

I have a friend who was diving and was very attentive to his SPG. But, it was his first time diving doubles in the ocean. He was used to being limited by his air. He monitored his SPG like a hawk and totally forgot to pay attention to his NDL. He racked up quite a bit of deco before he noticed. Fortunately, he handled it calmly and correctly AND had plenty of gas to actually do all the deco.

What I don't see is what scootering and getting bent has to do with the topic of this thread.

 

[elan]

Yes that's what happens. There are 2 factors there. 1. You do not work so no CO2 production and thus less breathing. 2. You do not need to be precisely neutrally buoyant as you can do minor compensation of the buoyancy with the scooter so the gas is not spent for maintaining buoyancy.

 

[Oldbear]

I did 6 dives over this past weekend. All in the same configuration (double steel 120s, 5mm wetsuit).

5 of the dives, I was working with a student. The 6th dive (actually, dive #4 - last dive on Saturday) I got in by myself and did a 45 minute run driving my BlackTip scooter.

I downloaded all my dives and happened to look at my gas consumption data.

For the 5 dives not scootering, my RMV ranged from 0.58 to 0.63, with an average of 0.61 cubic feet per minute. Very consistent. Surprising, to me, really, considering some dives I swam a short way and then mostly just hovered next to a platform, but other dives I was swimming (fairly slowly) the whole time.

On the 1 dive scootering, my RMV was 0.36. LOL! Went from 1246psi to 860 in 45 minutes, with an average depth of 23 feet.

Awesome how much scootering helps extend my gas!

Not only does your RMV drop with DPVs, up your Nitrogen Uptake also drops which lends itself to its own host of benefits.

 

[_Ralph]

Looooooooong Scooter dives on my mCCR, I have to burp out excess O2 every once in a while. Once I’m off the trigger and kicking like a peasant, it’s a different story…


_R