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Tank sizes need not be the same. What's important is having an idea what a person's consumption rate is before the dive, and planning your depth and time limits accordingly. With newer divers, that's difficult to figure out because they don't have enough data to work with.
What good will that do you? Suppose halfway through the dive you check your buddy's SPG and they've used up 80% of their available gas supply? Isn't that a little late to be checking? Checks should be made from the beginning of the dive, and periodically as the dive progresses. What you're doing is establishing a comparison of their rate and yours.
NO they don't.
Nonsense ... a pony is a redundant air source. It's appropriate for pretty much any recreational diving. And like all pieces of gear it has advantages and drawbacks. If you're going to carry one, you need to know what those are, and use the tool appropriately.
More nonsense. When you turn the dive depends entirely on your planned dive profile. In a simple out and back profile, you can divide by two ... but only after factoring in both your planned reserve (500 psi) and how much you will need for a safety stop. Otherwise, you're planning on ending the dive with an empty tank.
What if one reached the 1/2-way point much faster? What if that person got distracted and forgot to notice?
No ... by the time you are at 500 psi you should be on the surface..
Irrelevent.
A 3-person team can be managed easily and successfully if you know how. Where a lot of people get into trouble is not understanding what it takes. It starts by defining positions ... who's going to be in the middle, and which side each of the other two divers will be on. As the dive progresses, each diver is responsible for being where they are supposed to be. It makes keeping track of each other much simpler. It does increase task-loading, as you now have to keep an eye on both of your team mates. But with a little practice this isn't any more difficult than managing a 2-person team. It's not advisable for newer divers because it takes a higher level of awareness and communication skills than a 2-person team ... and that usually comes with practice. But under properly managed circumstances (a shallower, easier dive plan) it's a great way to help develop those skills. You have to be committed to the notion of diving as a team, however, as opposed to three people being in the water together in roughly the same place.
Well, this might have something to do with the ratio of novices to experienced divers overall.
Not necessarily ... there are a lot of factors that go into how much air a person is going to consume. Relative size is just one of those factors. A person's physical condition, stress level, fatigue level, and skill level are also major contributors. I'm a pretty big person, and often use less air than a lot of people half my size.
It's better, still, to gain some knowledge that will help you make a plan that works for all of the divers involved. One doesn't need special procedures ... they just need to understand the basics of gas management, and apply those basics to their dive plan.
I have no idea what you're talking about ... and I doubt you do either. Mentors are, have always been, and will always be, the backbone of scuba learning. The best thing a new diver can possibly do is hook up with a more experienced diver and go log some bottom time. You'll learn things that rarely, if ever, get covered in a class ... and things you'll never learn from another novice diver.
Unless, of course, you are clueless to begin with ...
While a lot of these comments are highly entertaining, they are ... to say the least ... also highly misleading ...
Tank sizes need not be the same. What's important is having an idea what a person's consumption rate is before the dive, and planning your depth and time limits accordingly. With newer divers, that's difficult to figure out because they don't have enough data to work with.
As for checking his gauge, it is a good idea to ask a new diver their air pressure frequently ... every few minutes at least. You then compare it to your own consumption. That will give you a basis for comparison. After taking two or three data points, you will be able to estimate at any given time what their tank pressure is likely going to be before you even ask.
What good will that do you? Suppose halfway through the dive you check your buddy's SPG and they've used up 80% of their available gas supply? Isn't that a little late to be checking? Checks should be made from the beginning of the dive, and periodically as the dive progresses. What you're doing is establishing a comparison of their rate and yours.
NO they don't.
Nonsense ... a pony is a redundant air source. It's appropriate for pretty much any recreational diving. And like all pieces of gear it has advantages and drawbacks. If you're going to carry one, you need to know what those are, and use the tool appropriately.
As for size ... how much reserve air you will need depends on both your consumption rate and planned dive profile. For some dives, a smaller bottle will be all you'll need. For deeper dives, a larger bottle may be a more appropriate choice.
More nonsense. When you turn the dive depends entirely on your planned dive profile. In a simple out and back profile, you can divide by two ... but only after factoring in both your planned reserve (500 psi) and how much you will need for a safety stop. Otherwise, you're planning on ending the dive with an empty tank.
Since most people don't do simple out and back dives, it becomes a little (but not much) more complex than that. Consider that you'll generally consume about as much getting back as you used going out. Let's say that's 700 psi. Add your reserve (500 psi) and what you will need for a safety stop (let's say 200 psi for example) ... and your turn pressure is the sum of all of those (in this case, 1400 psi).
Turn pressure will ALWAYS depend on both your profile and gas consumption rate. Also don't forget to factor in conditions, such as current, that will affect your consumption rate. This is one of the reasons why we teach new divers to dive against the current first ... so that they will use less air riding the current coming back.
What if one reached the 1/2-way point much faster? What if that person got distracted and forgot to notice?
You communicate with each other more frequently than that ... starting before you begin the dive by establishing who's got the most gas. The person with the least is likely to be the person controlling the turn. Then, once you begin the dive, check with each other every few minutes. Compare your dive buddy's consumption to yours. If he's going through gas faster than you are, then you KNOW that you don't want to wait till you hit turn pressure ... your buddy then has not only their own awareness to rely on, but yours to remind them if you think they might be getting close.
No ... by the time you are at 500 psi you should be on the surface..
Irrelevent.
A 3-person team can be managed easily and successfully if you know how. Where a lot of people get into trouble is not understanding what it takes. It starts by defining positions ... who's going to be in the middle, and which side each of the other two divers will be on. As the dive progresses, each diver is responsible for being where they are supposed to be. It makes keeping track of each other much simpler. It does increase task-loading, as you now have to keep an eye on both of your team mates. But with a little practice this isn't any more difficult than managing a 2-person team. It's not advisable for newer divers because it takes a higher level of awareness and communication skills than a 2-person team ... and that usually comes with practice. But under properly managed circumstances (a shallower, easier dive plan) it's a great way to help develop those skills. You have to be committed to the notion of diving as a team, however, as opposed to three people being in the water together in roughly the same place.
Well, this might have something to do with the ratio of novices to experienced divers overall.
Not necessarily ... there are a lot of factors that go into how much air a person is going to consume. Relative size is just one of those factors. A person's physical condition, stress level, fatigue level, and skill level are also major contributors. I'm a pretty big person, and often use less air than a lot of people half my size.
It's better, still, to gain some knowledge that will help you make a plan that works for all of the divers involved. One doesn't need special procedures ... they just need to understand the basics of gas management, and apply those basics to their dive plan.
I have no idea what you're talking about ... and I doubt you do either. Mentors are, have always been, and will always be, the backbone of scuba learning. The best thing a new diver can possibly do is hook up with a more experienced diver and go log some bottom time. You'll learn things that rarely, if ever, get covered in a class ... and things you'll never learn from another novice diver.
Unless, of course, you are clueless to begin with ...
To the OP ... you will see a link in my signature to my web site. If you go there and click on the Articles tab, you will find an article on gas management. You will find other articles on aspects of buddy diving. Please feel free to copy these articles (there's a link at the end of each that will let you print a PDF file), read them, and share them with your dive buddies. It may help you avoid situations like this in the future.
... Bob (Grateful Diver)
Taking your advice is exactly what worries me. I don't know if this is all a game to you ... or if you honestly believe the things you write. But I'd hate to think that some inexperienced diver is going to take your advice seriously and end up hurting themselves.Good advice, NWGD. If the O/P takes my advice then he will certainly take yours also.
