"Check bubbles"

[Sam Miller III]

It was super easy to just follow the ascent rate of the smallest bubbles when the rate was 60'/minute (1 second/foot). I stopped even looking at my watch and depth gauge after a few dozen dives and always was within a few seconds after reaching the surface or decompression stop, no calculations necessary. I have not been able to find small enough bubbles for the current 30'/minute rate. The "smallest" or 60'/minute bubbles are a little smaller than a pencil eraser. I suspect the phrase is a remnant from the faster ascent rate. I image that the surface tension of air and water prevents 30'/minute bubbles from forming.

great comment
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1) Bubbles always rise to surface...even in OZ
a) check orientation with bubbles
b) check assent rate with bubbles
c) check for equipment leaks with bubbles

Per LA County Department of Parks and Recreation, the first and undisputedly most difficult civilian dive training program's manual " "Underwater Safety Manual "" first edition dated July 1954, page 58,

"Never ascend faster than 25 foot per minute. The assent rate should be leisurely and never forced. Never "shoot to the surface. Thumb rule; Never pass your small bubbles on assent"

Recall that in 1954, recreational diving was in its infancy ..crude or yet to be developed equipment Kinda like when Lindberg few the Atlantic...

sdm

 

[psdiver102]

I started diving before computers were mainstream. the rule was to never ascend faster than your bubbles.

 

[Akimbo]

…
"Never ascend faster than 25 foot per minute. The assent rate should be leisurely and never forced. Never "shoot to the surface. Thumb rule; Never pass your small bubbles on assent"…

25’/minute was before my time but a lot of my Navy instructors had to deal with it. Twenty five seems like a nice easy number until you try to make it fit into 60 seconds. Pulling up umbilical as a tender, ascending in SCUBA, or venting a chamber at 0.4166'/second is challenging. At least 30'/second is manageable without a calculator and pre-printed table.

Note to younger divers:
SCUBA was originally an acronym (Self-Contained Underwater Breathing Apparatus) for pure oxygen closed-circuit rebreathers developed by Dr. Christian Lambertsen in the 1940s (the acronym came along in 1952). SCUBA quickly came to include open-circuit systems, Cousteau’s Aqualung, in the US Navy and the public. The word "Scuba" evolved around the 1980-90s to mean open-circuit underwater breathing systems to most divers today.

 

[Sam Miller III]

Akimbo, Yesterday at 1:24 PM Report

"Note to younger divers:
SCUBA was originally an acronym (Self-Contained Underwater Breathing Apparatus) for pure oxygen closed-circuit rebreathers developed by Dr. Christian Lambertsen in the 1940s (the acronym came along in 1952). SCUBA quickly came to include open-circuit systems, Cousteau’s Aqualung, in the US Navy and the public. The word "Scuba" evolved around the 1980-90s to mean open-circuit underwater breathing systems to most divers today."
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My response was too historically accurate and of no value to the readers

sdm