open/close

Website Options

Options below affect the visual display. Choices are stored using browser cookies.

  • The low bandwidth option causes most images to disappear and stops external fonts from loading.

  • The underlined links option causes all website links to become underlined, making them easier to distinguish.

  • The high contrast option causes colors to change to mostly black and white.

Utility Navigation

Reserve Air Supply System (RASS) to the Surface

2015
Oct 21

Video Display Options

  • YouTube
  • HTML5
  • Why choose?
close

The current state of video display on the web provides many challenges. If this website contains a YouTube video, we default to it since it is more likely to work in your choice of device/browser. That may not provide the experience you prefer, so we offer the option to choose your display: YouTube or HTML5. Please note the HTML5 video option may not work at all in some browsers/devices. If you cannot view the video you can download it from our video repository.

Transcript Content

WEBVTT

00:00:05.000 --> 00:00:07.000
[underwater exhalation]

00:00:11.466 --> 00:00:17.599
At NOAA, when doing working dives or in
situations with limited visibility, overhead
environments, or where you can be separated

00:00:17.600 --> 00:00:23.033
from you dive buddy, divers are required to
carry a redundant air supply system.

00:00:23.033 --> 00:00:25.799
At NOAA, we call this a RASS.

00:00:25.800 --> 00:00:32.566
Ideally, all divers on all dives should be self-
sufficient and carry a RASS. You'll be happy you
had one if you ever run out of air.

00:00:34.033 --> 00:00:36.466
The video we are about to see is RASS to the
surface.

00:00:36.466 --> 00:00:40.432
So here a diver has run out of air and there's
been a buddy separation,

00:00:40.433 --> 00:00:42.766
so the diver must make it to the surface.

00:00:42.766 --> 00:00:44.932
Here the diver has run out of air...

00:00:44.966 --> 00:00:48.866
Now, here we find a "known". We know the
bottom of the cylinder.

00:00:48.866 --> 00:00:57.332
Once you find the bottom of the cylinder you
can find the rest of the components. So this is a
habit we're starting early on in all divers.

00:00:57.333 --> 00:01:00.966
Later on if you go to do decompression diving
you might be wearing a sling bottle on the side.

00:01:00.966 --> 00:01:04.166
This might be required decompression gas.

00:01:04.166 --> 00:01:07.499
Or you might have a ceiling or overhead stops
required.

00:01:08.100 --> 00:01:09.566
So we start habits here.

00:01:09.566 --> 00:01:15.466
Find the bottom of the cylinder. From the bottom
of the cylinder you can find the second stage.

00:01:15.466 --> 00:01:18.466
From the second stage you can find the on/off
valve.

00:01:18.466 --> 00:01:22.732
From the on/off valve you know we are at the
first stage, from the first stage you can find the
pressure gauge.

00:01:22.733 --> 00:01:29.266
so from one known location you can find all the
components on the pony bottle. So let's watch
all those steps.

00:01:29.266 --> 00:01:34.032
From a known, to the on/off valve, from the
on/off valve, to the second stage,

00:01:34.033 --> 00:01:35.466
purge it,

00:01:35.466 --> 00:01:37.632
put it in your mouth and breathe from it.

00:01:37.633 --> 00:01:39.599
any time a diver

00:01:39.600 --> 00:01:45.100
doesn't have a second stage in their mouth they
need to be blowing a steady stream of bubbles.

00:01:45.100 --> 00:01:54.500
So even in between the second stage and orally
inflating the BC there's still a steady stream of
bubbles coming out of the diver's mouth.

00:01:54.500 --> 00:01:58.500
Here we are adding 2 to 3 breaths to the BC

00:01:58.500 --> 00:02:03.066
and you're catching that air inside your BC. This
is going to make your ascent much easier.

00:02:03.066 --> 00:02:07.666
That air that you've captured inside your BC is
going to expand on your way to the surface.

00:02:07.666 --> 00:02:15.666
Hand positions. Here we have the right hand
with a closed fist above our head. A closed fist
protects your fingers.

00:02:15.666 --> 00:02:19.866
A closed fist also protects your head from
overhead obstructions.

00:02:19.866 --> 00:02:26.399
your left hand holds the BCD inflator/deflator at
the highest point above your left shoulder.

00:02:26.400 --> 00:02:31.600
A couple reasons for doing this: as you're
ascending to the surface the air trapped inside
your BC

00:02:31.600 --> 00:02:36.833
is going to expand. You may need to vent some
air from your BC to slow down your ascent.

00:02:36.833 --> 00:02:38.833
also when you get to the surface

00:02:38.833 --> 00:02:45.499
you have to orally inflate your BC, so when you
get to the surface you've already located the
thing you have to blow air into.

00:02:45.500 --> 00:02:52.166
That's the alternate air source inflator or the
second stage located in your left hand.

00:02:52.166 --> 00:03:00.699
Here you see as the diver ascends to the
surface, less and less effort is required. The air
trapped in the BC is starting to take over.

00:03:00.700 --> 00:03:07.233
Still, when the diver gets to the surface go
ahead and take the second stage out and you
take breaths from ambient air

00:03:07.233 --> 00:03:11.499
and you blow that air into your BC.

00:03:14.433 --> 00:03:18.199
Once you are at the surface, go ahead and
ditch the second stage

00:03:18.200 --> 00:03:24.666
taking big breaths from ambient air and pushing
the yellow button directly in front of the
mouthpiece with your two fingers.

00:03:24.666 --> 00:03:30.432
Only blow when you're pushing the button, that
will capture air inside your BC.

00:03:30.433 --> 00:03:32.633
The skill is over when the diver is positively
buoyant.

Closed Caption File

Topics

Operation

Topics

Audience tags

Share

  • Facebook
  • Twitter
  • LinkedIn
  • Twitter

The information provided using this web site is only intended to be general summary information to the public. It is not intended to take the place of either written law or regulations.

Neither NOAA, the OMAO, the individuals featured in the videos, nor any other party associated with the production of these videos accept responsibility for any accident or injury resulting from the use of materials contained herein.

Information in these videos is current as of the date of production. Although we try to keep this information up-to-date and accurate, neither NOAA, the OMAO, nor any agency, officer, or employee thereof warrants the accuracy, completeness, or usefulness of any information, products, or processes disclosed herein, and shall not be held responsible for any losses caused by reliance on the accuracy, reliability or timeliness of such information. Portions of such information may be incorrect or out of date. Any person or entity that relies on any information obtained from the instructional videos herein does so at his or her own risk.

The views and opinions of authors expressed on OMAO websites do not necessarily state or reflect those of the U.S. Government, and they may not be used for advertising or product endorsement purposes.

OMAO makes every effort to provide virus-free files but does not guarantee uncorrupted files.

You are here: https://www.omao.noaa.gov/find/media/video/redundant-air-supply-system-rass-surface
Reviewed: June 20, 2016. Contact us with page issues.

*ac
"Access controlled" content.
top