I do two basic types of dives that require deco
1 - Shallow long dives 100-150 feet on wrecks time varies based on desired penetration and the bottom gas is usually air
2 - Shorter deeper dives 300 - 400 feet on Trimix
I both cases I tend to use the same general configuration of deco bottles, gases, etc. with some slight variances.
On my back twin 112's, 95's or 80's depending on depth or time. I like the aluminum 80's for beach dives
The mix in them will again depend on my dive profile usually a Trimix selection ranging from 21/10 to 10/60, my 80's I will put just air in sometimes as well. PO2 no more than 1.4 often less
On my left side is my travel gas general EAN 32 or 36 stored in aluminum 80. I like my PO2 to be no more than 1.4 on descent [I usually descend at 100/min] and 1.6 on deco
On my right side can be one or two bottles depending on my profile of course, an aluminum 80 is the usual package with 80% in it. Then sometimes I will add aluminum 40 with 100% on top of it.
My deco procedure and profile
I use Voyager software to plan my dives and variances [i.e. lose a gas, longer time, deeper dive]
I print a profile of all the variances, laminate it and take it with me. Hopefully never to use them.
I have a wrist slate were I print my dive profile, this is two pieces of PVC piping one laid on top of the other then attached to my arm with velcro. This way it opens up like a laptop. I then have three surfaces to write on.
The top one is my profile; the second one is my bailout if I loose my travel gas [36%]. Or deco gas [80%]. Profiles on my slate have no variances for dive time or depth. The third is for communication with the dive team.
Deep stops
Within this is as big of a debate as the long hose. I believe in deep stops [its ok if you don't] deep stops are such a theory and with all the good print on it, not much is written about how to figure them in or calculate them. What I do to figure my deep stops is this. I take half the distance between my planned depth and my first deco stop add that to my required deco stop for one minute then the same again between that stop and my first deco stop and so on until I hit my first required deco stop. For example a dive to 300 ft with a first required deco stop at 140. I would add stops at the following depths 220, 180, & 150
Descent / ascent rates
I descend at a rate of 100 ft/min until my PN2 reaches 4.3 or 150ft END then I slow down so as to word of the nitrogen demons
Don't get me wrong here I would prefer an END of 100 - 130 ft
My ascent is about 60ft/min until my first required deco stop then I slow down to about 45 ft/min until about 60ft then I am at 30ft or less / min. I play a little game and see how long it can take me to ascend the ten feet to my next deco. The last twenty feet I just don't want to move cause then my dive will be over.
Hydration, potty, food, boredom
I bring bottled water with me; so far it has worked out well I dont start drinking any until I am above 30 ft. I am still experimenting here. Potty = pee valve, I hate diapers
Food = Power Bars peanut butter ones are great and water does not effect them. Boredom = stay off a rope, deco up a wall or slope and make it part of the dive. If its Open Ocean or a line then its a Zen dive were you can talk to yourself for a couple of hours
Obviously I have left stuff out and made some quick assumptions just for discussion on deco purposes. Every dive and the factors associated with that dive are different.
1 - Shallow long dives 100-150 feet on wrecks time varies based on desired penetration and the bottom gas is usually air
2 - Shorter deeper dives 300 - 400 feet on Trimix
I both cases I tend to use the same general configuration of deco bottles, gases, etc. with some slight variances.
On my back twin 112's, 95's or 80's depending on depth or time. I like the aluminum 80's for beach dives
The mix in them will again depend on my dive profile usually a Trimix selection ranging from 21/10 to 10/60, my 80's I will put just air in sometimes as well. PO2 no more than 1.4 often less
On my left side is my travel gas general EAN 32 or 36 stored in aluminum 80. I like my PO2 to be no more than 1.4 on descent [I usually descend at 100/min] and 1.6 on deco
On my right side can be one or two bottles depending on my profile of course, an aluminum 80 is the usual package with 80% in it. Then sometimes I will add aluminum 40 with 100% on top of it.
My deco procedure and profile
I use Voyager software to plan my dives and variances [i.e. lose a gas, longer time, deeper dive]
I print a profile of all the variances, laminate it and take it with me. Hopefully never to use them.
I have a wrist slate were I print my dive profile, this is two pieces of PVC piping one laid on top of the other then attached to my arm with velcro. This way it opens up like a laptop. I then have three surfaces to write on.
The top one is my profile; the second one is my bailout if I loose my travel gas [36%]. Or deco gas [80%]. Profiles on my slate have no variances for dive time or depth. The third is for communication with the dive team.
Deep stops
Within this is as big of a debate as the long hose. I believe in deep stops [its ok if you don't] deep stops are such a theory and with all the good print on it, not much is written about how to figure them in or calculate them. What I do to figure my deep stops is this. I take half the distance between my planned depth and my first deco stop add that to my required deco stop for one minute then the same again between that stop and my first deco stop and so on until I hit my first required deco stop. For example a dive to 300 ft with a first required deco stop at 140. I would add stops at the following depths 220, 180, & 150
Descent / ascent rates
I descend at a rate of 100 ft/min until my PN2 reaches 4.3 or 150ft END then I slow down so as to word of the nitrogen demons
Don't get me wrong here I would prefer an END of 100 - 130 ft
My ascent is about 60ft/min until my first required deco stop then I slow down to about 45 ft/min until about 60ft then I am at 30ft or less / min. I play a little game and see how long it can take me to ascend the ten feet to my next deco. The last twenty feet I just don't want to move cause then my dive will be over.
Hydration, potty, food, boredom
I bring bottled water with me; so far it has worked out well I dont start drinking any until I am above 30 ft. I am still experimenting here. Potty = pee valve, I hate diapers
Food = Power Bars peanut butter ones are great and water does not effect them. Boredom = stay off a rope, deco up a wall or slope and make it part of the dive. If its Open Ocean or a line then its a Zen dive were you can talk to yourself for a couple of hours
Obviously I have left stuff out and made some quick assumptions just for discussion on deco purposes. Every dive and the factors associated with that dive are different.
