Bad scuba advice you've received

[PBcatfish]

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Heavy gear drysuits just attach to the breast plate that the helmet attaches to. No neck dam of any kind.

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7:35 - "check this by blowing a mouth full of cigarette smoke into the valve"
That's some advice that probably didn't make it to the more modern training courses.

 

[Akimbo]

7:35 - "check this by blowing a mouth full of cigarette smoke into the valve"
That's some advice that probably didn't make it to the more modern training courses.

Check valves still have to be checked. We can pressurize the check valve by opening the bailout valve when the umbilical is not connected on a modern hat or mask.

Here is a nasty true story on what happens when the check valve fails:

Innovations
Bev and Bob constantly worked to improve the lightweight fiberglass masks and managed to make a meager living. One day, an abalone diver named Walt Swenson came to their shop. His whole face was badly bruised and the whites of his eyes were blood-red. He was not a happy customer. Walt was using one of their freeflow masks when the hose blew near the surface and the check valve on the mask failed. It sucked both of his eyes out of their sockets but he managed to pry the mask off his face before it starting sending soft tissue up the hose.

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[jadairiii]

....but with nitrox this is absolutely true for a partial pressure fill that was just done....

There could be lots of reasons for off readings, but needing to roll you tanks aint one of them. You blast high pressure air (from the compressor) through a valve and the dip tube on top of a couple hundred pounds of O2, its mixed. Talk to a physicist about this.

With everything, there is a kernel of truth here, huge commercial gas companies that mix gas in giant tanks do get stratification issues. (not to be confused with the cryo-stir of the Apollo O2 tanks) But not is a scuba tank.

 

[formernuke]

I have had very different readings with trimix fills after about 12 hours plus a one hour total drive time.

 

[boulderjohn]

I have had very different readings with trimix fills after about 12 hours plus a one hour total drive time.

Yep.

I don't even bother measuring trimix fills (via partial pressure blending) until well after filling.

I will get different readings for nitrox after a lesser wait.

 

[Nedster]

Get it right. It's called the 'up' button)))

 

[alanchang]

As for the bad advice:

Be back on the boat with 500psi

How's that a problem? My buddy surfaced with 500psi regularly for deeper dives cus even with a cave-filled HP100(4200psi) and low SAC, my buddy can only stay 15-20mins at 120ft. That's too short of a dive and 15min is far from enough to finish seeing a 200ft long shipwreck. If surface more than 500psi, it will be a dive that's too short to be worth it. For shallow dives(60ft), I ask my buddy to signal me at 500 psi(Safety stops) and surface at 200 psi. This is only for open water tho. No overhead.

 

[Alekseolsen]

How's that a problem? My buddy surfaced with 500psi regularly for deeper dives cus even with a cave-filled HP100(4200psi) and low SAC, my buddy can only stay 15-20mins at 120ft. That's too short of a dive and 15min is far from enough to finish seeing a 200ft long shipwreck. If surface more than 500psi, it will be a dive that's too short to be worth it. For shallow dives(60ft), I ask my buddy to signal me at 500 psi(Safety stops) and surface at 200 psi. This is only for open water tho. No overhead.

Using "I need all the reserve gas to carry out the dive" as a reason for not having reserve gas seems a bit off. IMHO a better approach would be more or larger tanks.
IMHO slinging an S80 wouldn't be an issue, altough there's plenty of people here that believe that would require a course.

 

[alanchang]

Using "I need all the reserve gas to carry out the dive" as a reason for not having reserve gas seems a bit off. IMHO a better approach would be more or larger tanks.
IMHO slinging an S80 wouldn't be an issue, altough there's plenty of people here that believe that would require a course.

While I am using a CCR and I’m certified to deco with it so it’s not a problem of mine. My buddy usually dives singles and we get along with each other really well so I enjoyed diving with him. Just need to push it a bit by overfilling a little and use up the tank more

 

[steinbil]

It's not a big deal if you go past your NDL and go into deco, it'll probably clear on the way back.