Tag Archives: Deep Stops

Deep Extended Range

Everything ready to go
Enough Bottles

UWE and Ocean Quest are excited to announce we have three new Deep Extended Range Divers.  Roland, Mike and Travis completed an intensive three days of training.  First was the new dive theory that you learn in the classroom.  This is the PADI Deep course on steroids.  We cover the normal deep knowledge development but then we go in depth in your SAC rate calculation, Deep Stops, as well as the importance of Awareness and advanced Propulsion techniques such as the modified Frog kick, helicopter turns and then of course the reverse fining.

We completed this section with video’s and of course some white board work.  From there we went into Stage Bottle Set up, NOTX switches and then we took our time and calculated and Extended Range dive using Enriched air and doing exact gas calculations to ensure we had the proper amount of gas with us, we calculated our turn pressure, rock bottom and then our advanced safety stop techniques.  During this course it is important that we utilize Deep stops, and then we do a minimum 6 – 8 safety stop in order to make sure we have off gassed enough Nitrogen in order to exit the water safely.

Multiple Cylinders in Sidemount
Sidemount configuration

Saturday was the first day in the water, and the first occasion that the students had the opportunity to dive with stage bottles.  In the Deep Extended Range course it’s important to know proper configuration in order to ensure we have enough safety gas available just in case there is failure.  Once under the water we worked on fining techniques, and then we did a SAC swim so everyone could get enough data to calculate their gas requirements.  We did bag drills where the diver needs to successfully launch their SMB, but also maintain their current depth and position, once again Awareness is front and center in this kind of training.  Once the Bags were deployed we did our first stops at 30 feet, where the students needed to do the correct NOTOX Switch to their safety cylinder and ensure that a proper switch was completed.

Dive two on the Saturday we did our descent to 100 feet, and did the skills needed in dive two of the PADI Deep course, and then with the ascent we did deep stops, and out of air and share air drills in the 20 foot level, once again ensuring our Awareness was not affected.  Well done for Day one of the Deep Extended Course!

Gas Mixture analysis
Roland confirming his Gas Mixture

Day two, we all met at Ocean Quest in order to analysis our gases, on this day we would be diving on 30% Enriched Air for the bottom gas, and our stage bottles would have 40 Enriched Air for our second level and gas switch.  Everyone did an awesome job confirming their gas and then planning the dive.  The plan was to descend down to 120 feet, and spend approximately 11 minutes at depth then ascent to 60 ft and do a gas switch to the 40% cylinder.  This effectively gave us about 60 minutes of allowable No Decompression Limit

Congratulations to Everyone
Congratulations to Everyone

once to conducted our gas switch.  Our plan was to be at the safety stop with 2000 psi left in the stage bottle and then do our extended safety stop on the back gas.

The dive plan though what seemed complicated was executed perfectly.  We conducted one more dive at Tuwanek, and on completion Ocean Quest had 3 new Deep Extended Range divers!! Well done guys!!

Deep Stop RGBM Algorithm

Classical Haldane

Classical Haldane-type decompression calculation assumes that all gas is dissolved into the tissues, and remains dissolved as long as the maximum tissue tensions are not exceeded.  Bubbles are assumed to form only when the ascent rate or the m-values are exceeded.  As the pressure gradient is invertedly proportional to the surrounding pressure, the diver is brought as shallow as possible, as fast as possible, in order to maximize offgasing.

Doppler-studies show, that microbubbles are present on all doves.  Therefore the effects of free gas need also to be considered in decompression calculations

Suunto RGBM

The Suunto RGBM was designed to protect the recreational diver from the effects of micro-bubble build up.  It incorporates a bubble-factor based tracking system to adapt the decompression requirement based on conduct dive profiles.  The maximum ascent provides maximum offgassing and a clean decompression curve.  A 3min recommended safety stop is added to deal with adverse ascent rate violation.  An extended surface interval is promoted when microbubbling is present.



Suunto Deep Stop RGBM

The Suunto Deep Stop RGBM algorithm increases microbubble suppression on deep dives even further by introducing iterative deep stops.

The first deep stop is placed at half the pressure difference between your maximum depth and the ceiling depth.  Once the deep stop depth is attained, the next deep stop will again be introduced half-way to the ceiling, and so on.  Once the ceiling depth is reached, continous decompression is employed for staging the end of the profile.

In the Suunto D9 and Suunto Vytec DS the user can choose between the familiar Safety Stop providing Suunto RGBM, or the new Deep Stop RGBM.