Deco in Mexican caves
Contrary to popular opinion it is possible to get into Deco in the caves of Quiatana Roo. This becomes more apparent once you start extending the limits of available penetration gas. Time at depth is the bigger factor in decompression that depth itself! When you start to look at averages in some of the moderately deep cave environments of the area then it is very possible that after a nice long dive you may be faced with a decompression stop upon exit. Better to plan for this than be caught short at 6m!
Last year Mike and I prepped, planned and packed our poor little rental car with back gas, two stages each and two O2 bottles. Aside from lunch there really was not much room for more.
We planned the biggest dive I have done on this site! Start in B tunnel and jump to E tunnel. then drop a stage, switch and move forward jumping onto the main line way back in to the Battleship room. This was to be a 75 minute penetration with considerations of elevated consumption, restrictions, decompression and narcosis... Yes that's right Narcosis! GUE treat O2 as narcotic and after starting to dive Trimix in shallower ranges you start to realise quite what an effect it has on you.
Mayan Blue is a site of massive power cave with jumps off into highly decorated restricted areas. The passages constantly plunge from Fresh to salt water through the Halocline, changing the cave from dark, vacuous primary light sucking fresh layers to an incandescent blue and bleached white layer of light silt and sheer beauty!
SO... The Deco? Our maximum depth was 24m, We spent two and a half hours in a cave! 150 mins! How do you work it out? We use average depths, this enables us to use decompression software to see what our limits are. Once you understand the relationship between average depth and set points, it frees a diver up to flex and adapt their plans on the fly! Also we dive Nitrox within ranges that will optimise available bottom time, at 18m you almost double your bottom time! Through proper planning and training Mike and I worked out or Deco and for the profile achieved and it gave us a 10 minute stop on O2 at 6m. not a long one but it would have been far more if we had not planned and used all options available to a diver!
We are looking forward to getting back to Mexico in the summer of 2019 and to more excellent cave diving experiences! Watch this space for more from cave country!
*Thanks as always to Miguel Batey fro awesome images!