Question re: Bailout bottles
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gert7to3
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It looks like the H2Odessy and Zeagle Razor can be mounted on any size tank. So a small, light tank for travel and a larger tank for serious backup are both cost effective possibilities.
As for the critics of Spare Air, under many recreational diving conditions it will provide a margin of safety.
As for the critics of Spare Air, under many recreational diving conditions it will provide a margin of safety.
People seem to be calculating their Pony capacity needs based on their regular consumption rate or SAC. Remember your air consumption during an emergency will not be the same as a lazy drift dive where you are barely moving. It may be 3-4 times higher in times of stress. Find your worse air consumption rate and plan using that.
It is better to come out of the water with 1200 PSI unused than run out at 50'.
It is better to come out of the water with 1200 PSI unused than run out at 50'.
Darnold9999
Contributor
... or they are calculating it based on bailout only, a slightly slower than CESA ascent rate and accepting the risk. If I switch to my 6 cf bailout bottle, I am on my way to the surface, skipping the safety stop and ascending fairly quickly. If my 13 then a much slower ascent rate, but still skipping the safety stop. Neither gives me any time to solve a problem at depth, but both will get me to the surface from any rec depth - but it will be a risky ascent.
My point exactly. So get a gas volume on you that will support a slow and safe ascent rate, include the safety stop and take a greatly reduced risk... Avoiding an OOA situation by taking a DCS / AGE hit from a rapid ascent is not a good trade in my book; especially if diving alone.
"Do not be desirous of having things done quickly. Do not look at small advantages. Desire to have things done quickly prevents their being done thoroughly. Looking at small advantages prevents great affairs from being accomplished."
- Confucius (551 BC - 471 BC) Chinese Philosopher
Pardon my ignorence but why couldn't you do a safety stop with a 13 cf? You should have more than 5 min of air shouldn't you? This is assuming a depth of 60 ft. A 13cf is 16% of an aluminum 80. That would mean you are only getting 30 minutes off the tank at that rate. Sorry I don't have a 13cf but if it is truely not enough then I want to go bigger. I'm planing on upgrading and don't want to waste my time with something that is no real solution.
Darnold9999
Contributor
Again - bailout only - you choose a redundant size for your diving and I will choose mine. Please don't assume my (or anyones) choice is uninformed. The difference in my choice is the tradeoff between size, weight and the level of risk we are willing to entertain.
If there is air I will do my safety stop, but I don't figure it in to the planning. At 60 feet a 13 cf might give you air to do a safety stop - at 100 not so much, but it will get you to the surface reasonably comfortably - skipping the safety stop. At 130 feet you will get to the surface, but you will be in a hurry and you will be certainly skipping the safety stop. I actually wouldn't consider a 130 foot dive solo on a 13 cf bottle - the safety margin is too thin - for me.
The risk for dcs is there but for me low enough to accept. You calculations are obviously different - however you still accept some level of risk no matter what size bottle you carry. Does not make my calculation wrong, just different.
If there is air I will do my safety stop, but I don't figure it in to the planning. At 60 feet a 13 cf might give you air to do a safety stop - at 100 not so much, but it will get you to the surface reasonably comfortably - skipping the safety stop. At 130 feet you will get to the surface, but you will be in a hurry and you will be certainly skipping the safety stop. I actually wouldn't consider a 130 foot dive solo on a 13 cf bottle - the safety margin is too thin - for me.
The risk for dcs is there but for me low enough to accept. You calculations are obviously different - however you still accept some level of risk no matter what size bottle you carry. Does not make my calculation wrong, just different.
Darnold9999
Contributor
Depends what problem you are trying to solve. There are lots of people that won't dive solo with anything less than an AL 40 slung. This gives you lots of air to solve a problem, and then do a leasurly ascent, full safety stop and air for contingencies on the surface. I just do a different calculus. The chances of something going wrong are low to start with - a 13 cf will get me to the surface safely in most but not all of these situations. A 6 cf gets me to the surface in fewer situations so I only use it in tropical diving where I carry much less gear. A 40 will get you to the surface in more situations. You choice will depend on the level of risk you are willing to accept.
You do need to do the calculations and work within your comfort zone.
I'm not sure if your comment about uninformed choice was directed at me or not. I never said anything about it. I was only asking to see what the figures were in a real world situation. As I said I don't want to waste my money on a 13cf if I really should have bigger. I have never used one and have no first hand experience. I also suck at math so your figures my be more accuarate. I wanted to know how you did the math. I agree 130 seems further than I care to solo.
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