Oceans of Opportunity

today’s worst undersea threat | carbon dioxide

Since the start of the 21st century, rebreathers have become the accepted norm for pursuing more routine expeditious intervention of the ocean. This technology is quite simple, as it basically recycles the diver’s exhalations, removing poisonous CO2, then monitoring the gas, and providing some means to add oxygen that has been metabolized by the diver. While simple, this is powerful. Gas supplies no longer become a limiting factor for undersea intervention, and people can spend upwards of 6to 8 hours in the undersea environment. There are also physiological advantages.

Many improvements need to be made before a mass market opens up, which will be the catalyst needed to allow a major shift towards undersea colonization. Perhaps the most pressing issue that needs to be addressed is carbon dioxide. Chemical scrubbers used in rebreathers are not able to be gauged effectively across the wide range of operating conditions that they face including varied humidities, gas velocities across the bed, a range of pressures, and so on. It is then possible for carbon dioxide to ‘breakthrough’ a scrubber without the diver being aware, thus exposing him/her to a highly toxic situation. Likewise, carbon dioxide built up and retained in the body’s tissues while diving cannot be gauged. CO2 buildup in the tissues and in the breathing circuit (hypercarbia and/or hypercapnea respectively) are two of the worst threats facing today’s undersea explorers.

The below video is the best source of information on the subject and communicates the severity of this threat so very well.

CO2 Video from HSE

The best tip…dive conservatively, self-educate about the limits of carbon dioxide absorbants and scrubber design/efficiency under your range of operating conditions, and encourage those involved in R&D to make CO2 detection a top priority!

For discussion on the subject as of this writing, the following video from the 2008 Rebreather Summit sums up a variety of opinions from the experts:

Rebreather Diving Summit from Robert McClellan on Vimeo

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