Mission & Project Info | NOAA’s Aquarius Undersea Laboratory
Mission Blog

This being a test and evaluation mission, we wanted to test the full potential of the Inspiration rebreather and the software changes that so far, have made this possible. This meant diving our 6 hour excursion table and determining the canister duration under good conditions (warm water, light to moderate work pace) and assessing the average gas consumption. Without going into too much detail and risk boring those of you reading this, these are the basics of what we wanted to do.

Dive a partial pressure of oxygen (PPO2) depth equivalent or better than air (.90 in this case)

Take advantage of Aquarius excursion table of 95 fsw for 360 minutes (6 hours) PPO2 of .82

Stay within the NOAA oxygen toxicity units tables for single exposure at .90 of 6 hours 

Safely dive CO2 canister (fresh fill) based on the on board temperature stick icon

Start with full oxygen cylinder and full diluent cylinder

Determine operational risk management steps (i.e. bailout cylinders etc….)

And the results:

We dove a PPO2 range of .70 – .90 to a max depth of 90 fsw for a total of 360 minutes or 6 hours.  It was an extremely successful dive!  Everything came together… we’ve proven we can dive a commercial rebreather from Ambient Pressure Diving (The Inspiration) staying within established saturation and oxygen toxicity tables for 360 minutes or 6 hours straight without refilling oxygen or diluent cylinders.  A very important note to make is that the CO2 absorbent was fresh and unused, the temperature stick provided a guide as to duration of absorbent based on the exothermic reaction and a light to moderate work pace.

Once again… we showed today that we can safely dive the Inspiration out of Aquarius and saturation. And it is all documented for perpetuity.  Scientists and NASA Astronauts can benefit from this technology in many ways.  For scientists, time lost filling tanks is now gained doing science and the silent nature of the rebreather makes it advantageous for marine life studies.  NASA Astronauts can also gain time training rather than filling tanks and have the added analog of a closed circuit life support system on their back with a full face mask and communications.

 In closing, people that know me know how passionate and loyal I am about my work here at Aquarius.  While I helped make this mission happen, in reality there was so much involved in putting this together, no one person could have thought of everything. So it is with great pride and pleasure that I thank first and foremost our DIVE LOCKER at Aquarius.  Without them this could not have been possible. 

Special thanks to:

Craig Cooper,Otto Rutten, Jim Buckley, Ellen Prager, James Talacek, Mark Hulsbeck, Dominic Landucci, Justin Brown, Larry Ward, Nate Bender, Tim Roberts and Ryan LaPette.  Also, LT Johnston US Navy DMO.

A personal thanks goes out to my dive buddies at depth.

Tim Gallagher, Dewey Smith, Warren Miller (Inspiration instructor) and Doug Arnberg (Inspiration instructors)

Honorable mentions:

Martin Parker (Managing Director Ambient Pressure Diving)

Nigel Hester (Software specialist Ambient Pressure Diving)

David Burroughs (Hollis Industries for providing the MK-50 Full Face Mask with heads up display)

Jim Standing (Fourth Element wet suits for providing me with a wet suit that kept me warm for 6 hours / Thanks Jim)

Respectfully,
Roger Garcia
Diving Safety Officer / CHT
NOAA Undersea Research Center / Aquarius

Richard asks:Are your rebreathing divers hooked up by cable to Aquarius or do they have wireless communication? Does wireless work underwater?

Dear Richard,

No we are not connected or “hard wired” for communications this time.  Although we could be, and that type of underwater communication tends to be much clearer and louder.

In a sense we are wireless. We were wearing portable transceivers with microphones and headphones.  Although sound travels 4 times faster underwater, the portable transceivers tend to pick up lots of ambient noise. Subsequently, the communications aren’t as clear as being connected to a cable.  However, no matter what kind of communication equipment you have on, sometimes it’s nice to be able to talk underwater in many respects. 

Respectfully,
Roger Garcia
Diving Safety Officer / CHT
NOAA Undersea Research Center / Aquarius

Today was the day that would pave the way for rebreathers out of Aquarius if the calibration at depth worked properly. Using a 55% mix, to achieve a partial pressure of O2 of about 1.3, we calibrated the first unit. We all watched with anticipation, but not much doubt. It worked…. The unit calibrated properly and we had no reason to feel uncomfortable about the process. Ambient Pressure Diving did a tremendous job in modifying the vision electronics.

Our first dive was to 115 fsw max depth for 180 minutes with a partial pressure range of .70 to .95. Our excursion went very well and the units performed perfectly. The dive was extremely successful due to the initial first time calibration at depth with a dive computer and the Inspiration closed circuit rebreather.

Our second dive was to 70 fsw for 90 minutes, with our focus mainly on using a full face mask with a heads up display provided by Hollis Industries. Once again the units calibrated well and accurately. The communications worked fine as expected, it was mostly to ensure it could be done, but we had no reason to believe it would not work. The full face mask with the heads up display was an added bonus and I thought showed potential for future missions and dives. Good and successful day all around!

As of now I have 7 and one half hours logged on just one canister of carbon dioxide absorbent and used a total of about 2600 psig of oxygen. Very low gas consumption and I have no doubt that will be an asset for the future.

Roger Garcia
Diving Safety Officer / CHT
NOAA Undersea Research Center / Aquarius

Work began quickly:

Warren and Doug successfully installed the new software changes for the Inspiration rebreathers that will allow the vision electronics to function properly in saturation out of Aquarius. During our pre-dives it quickly became apparent that the new changes would work. After calibrating the units we swam around Aquarius for about 20 minutes focusing on the partial pressure of O2 on the displays. The 20 minute initial dive went well and showed promise for the upcoming dives.

After our first dive our confidence in the software change provided by Ambient Pressure Diving had grown and we prepped for a second afternoon dive. The units will be calibrated at depth tomorrow, but we dove the same partial pressures of O2 settings as the am dive. The dive was to 95 fsw for 120 minutes. The PPO2 range was from .70 to .90. I considered it a successful dive.

Roger Garcia
Diving Safety Officer / CHT
NOAA Undersea Research Center / Aquarius

Ron Peters asks: Just noticed three of your divers exiting the habitat. What rebreathers are they using. Are they CCR? Why did you select these particular units?

Dear Ron,

The rebreather is the Inspiration with the vision electronics.

Yes, it’s a closed circuit rebreather (CCR)

We chose the Inspiration mainly because the company, Ambient Pressure Diving (APD) was confident it could modify the existing “on board” computer and software to calibrate during saturation. The modification also allows us to turn the computer off during saturation. All dive computers do not allow a diver to turn it off during a dive… i.e. saturation.
There were other reasons too, like the canister duration and the ability to see how much CO2 absorbent was being consumed so to speak, due to it’s temperature stick inside the CO2 canister…

Roger Garcia
Diving Safety Officer, Aquarius Reef Base