What do you wish you could teach a recreational diver?
- Thread starter Ting Tong
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
fire_diver
Contributor
How to calculate air consumption rates and gas/dive planning.
- Messages
- 20,648
- Reaction score
- 15,146
- # of dives
- I'm a Fish!
your SAC is higher on descent because you are inflating your BCD which is more air consumption that you are used to, you are also likely over breathing quite a bit to counter your descent rate, it's not abnormal.
The general math is 3x your DAC *depth air consumption* rate at planned depth for safe ascent to the surface. This gives you your air, your buddies air and "oh sh!t air", and this is all still with ascending with at least 300psi in the tank, so factor that in as well.
Jim's book is the book of hard knocks, been there's and done that's..... A good primer though is the GUE recreational manual if you can get your hands on that. It's a bit gruff to most new divers, but it's good. The NASE one I think is pretty good as well
The general math is 3x your DAC *depth air consumption* rate at planned depth for safe ascent to the surface. This gives you your air, your buddies air and "oh sh!t air", and this is all still with ascending with at least 300psi in the tank, so factor that in as well.
Jim's book is the book of hard knocks, been there's and done that's..... A good primer though is the GUE recreational manual if you can get your hands on that. It's a bit gruff to most new divers, but it's good. The NASE one I think is pretty good as well
waterpirate
Contributor
To go " slow and easy with good technique " to steal a line from a SB legend. The whole scuba thing is not a race, but a journey. It is to be enjoyed and long lasting. Lastly technical diving is not a goal to be achieved, it is but a choice of path to travel.
YMMV
Eric
YMMV
Eric
- Messages
- 20,648
- Reaction score
- 15,146
- # of dives
- I'm a Fish!
slow and relaxed with good technique is the original quote, quote was coined by an old school cave diver and is still used extensively in the military
While it's not 'technical', I wish divers were taught proper breathing patterns and given a kind of benchmark for consumption. IMO 10L/min (3.5cbf/min) is a worthy benchmark.
Above all, I would like all our OW students to come away with a more proactive approach to diving than I did. The big difference between usual recreational diving and technical diving is that technical divers PLAN . . . they don't just jump in the water and swim around until they hit one of the possible limits. Technical divers know how deep they are going to go, how much time they intend to spend on the bottom, how they are going to execute their ascent, and how much gas they need to do all of that. In addition, they have given some thought to the likely problems that might occur during the dive, and they have a strategy in place to deal with each -- and whatever skills they need for those strategies, they have practiced.
As an example: You are on a charter boat in Hawaii, and they tell you they're going to do a drift dive off Red Hill. It's the second dive, so they tell you to watch your computer carefully so you don't go into deco. You jump in the water and follow the divemaster. The current starts to push the group apart, and you're anxious, because you don't really know where the guide is going. You don't know how long the dive is expected to last. You're watching your gas and your no-deco time to see if either is getting low.
The same dive, done differently: It's a drift dive off Red Hill. You ask the DM how deep he expects to go, and he says 60 feet. You plug in 60 feet in your dive computer's planning mode, and find out you have 45 minutes at that depth, given your previous dive. You check your tank, which is full, and you calculate your gas consumption at 3 ATA for 45 minutes and discover that, with a novice diver's gas consumption, you are woefully short of gas for that dive. You talk to the DM and ask him how long he expects the dive to run, and whether you will be at 60 feet the whole time, or if you will have an option to move shallower. You match his answers to your gas supply and figure out what you can do. You look along the reef and check your compass, so you know roughly what direction the dive will go; that way, if you get separated from the guide, you and your buddy can continue in the same direction.
See the difference? Thought given to the dive before you get in the water prevents problems. Discussing the dive with your buddy and clarifying a plan and signals and contingency procedures prevents misunderstanding and stress. The more you can do ahead of time, the smoother and more relaxed your dive will be.
BTW, here are a couple of great resources for reading material, including an excellent article on calculating gas consumption: www.nwgratefuldiver.com has a number of good articles, and so does www.divedir.com, under the "resources" tab. Those two sites should keep you busy for quite a while!
As an example: You are on a charter boat in Hawaii, and they tell you they're going to do a drift dive off Red Hill. It's the second dive, so they tell you to watch your computer carefully so you don't go into deco. You jump in the water and follow the divemaster. The current starts to push the group apart, and you're anxious, because you don't really know where the guide is going. You don't know how long the dive is expected to last. You're watching your gas and your no-deco time to see if either is getting low.
The same dive, done differently: It's a drift dive off Red Hill. You ask the DM how deep he expects to go, and he says 60 feet. You plug in 60 feet in your dive computer's planning mode, and find out you have 45 minutes at that depth, given your previous dive. You check your tank, which is full, and you calculate your gas consumption at 3 ATA for 45 minutes and discover that, with a novice diver's gas consumption, you are woefully short of gas for that dive. You talk to the DM and ask him how long he expects the dive to run, and whether you will be at 60 feet the whole time, or if you will have an option to move shallower. You match his answers to your gas supply and figure out what you can do. You look along the reef and check your compass, so you know roughly what direction the dive will go; that way, if you get separated from the guide, you and your buddy can continue in the same direction.
See the difference? Thought given to the dive before you get in the water prevents problems. Discussing the dive with your buddy and clarifying a plan and signals and contingency procedures prevents misunderstanding and stress. The more you can do ahead of time, the smoother and more relaxed your dive will be.
BTW, here are a couple of great resources for reading material, including an excellent article on calculating gas consumption: www.nwgratefuldiver.com has a number of good articles, and so does www.divedir.com, under the "resources" tab. Those two sites should keep you busy for quite a while!
Last edited:
Beyond what has already been mentioned, I'd say that proper buddy checks and a habit of running S drills along with other regular emergency drills(SMB deployment etc..) would rate pretty high on the list.
OP
Ting Tong
Contributor
Thanks, I will keep this in mind.
I have just ordered Jims book but it will take a little while to be delivered. Regarding the GUE manual, would I be correct in assuming it's this one?
https://www.globalunderwaterexplore...end-mind-fundamentals-recreational-diving-pdf
---------- Post added September 29th, 2014 at 06:38 PM ----------
Thanks for the links TSandM. I liked your example and will endevour to educate myself so that I will can be like diver as described in example dive 2 even if I just stay at the recreational level.
---------- Post added September 29th, 2014 at 06:50 PM ----------
Thank you for all the replies. It has really given me a lot clearer focus on what I need to concentrate on to further my diving knowledge and skills. It really is a case of what you don't know, you don't know.
Unfortunately I believe I am a product of a system that has been so watered down, that it's a little scary.
I will be diving in a couple of days and I have decided to dive with an instructor and work on the things that you have all brought to my attention. No course, no pretty card at the end, just some one on one time working out what I need to know. ie dive planning, consumption rates and minimum gas and of course my frog kicks.
- Messages
- 20,648
- Reaction score
- 15,146
- # of dives
- I'm a Fish!
that would be it, the DIR Fundamentals book is actually pretty good too, though it is just kind of explaining the gear configuration and a few other things, I think the Rec book would be better suited to what you're trying to gain. Nice thing is it appears to be a PDF so you don't have to wait on shipping.
Unfortunately your belief is correct and there is no chance that it can be undiluted.
Unfortunately your belief is correct and there is no chance that it can be undiluted.
Similar threads
