During my Advances OW course, it talked about altitude as being "anything over 1000feet" and to "limit daily diving to 2 dives at altitude".
Phoenix (lake Pleasant) is 1500+ feet and I KNOW people do more than "2 dives a day" around here ;)
So what do people really consider "altitude" and when does a person say "this is the most dives I should do in a day"?
ScubaSteve2000
April 2nd, 2009, 07:46 PM
Yes. Diving at Lake Pleasant is considered an altitude dive because it is over 1000 feet. My VT3 tells me so. It shows EL2.
I think the 2 dives per day maximum comes from PADI for training dives. The only limit to the number of dives in a day is your nitrogen loading (and O2 partial pressure for Nitrox users) and how many tanks you want to lug around.
If you're diving in San Deigo you may need to think about the time interval between your last dive and when you are driving home. And of course you should wait the requisite interval before you fly.
The most important thing to remember is to always dive within your limits. And it's never a bad thing to thumb a dive because you don't feel comfortable withit.
Steve.
scubajcf
April 2nd, 2009, 08:31 PM
Some tips for Altitude Diving.
Altitude Diving Tips and Refresher | Academy of Scuba (http://academyofscuba.com/blog/2009/03/04/altitude-diving-tips-and-refresher/)
Arizona Scuba Diving = Altitude Diving | Academy of Scuba (http://academyofscuba.com/blog/2009/03/07/arizona-scuba-diving-altitude-diving/)
If you have questions like this, you may want to discuss them more in-depth with your instructor.
BTW - PADI Recommends that divers at altitude should do no more than two dives a day (training or not). Yes, people do make more than two dives a day at Lake Pleasant.
Dive safe and keep asking the great questions!!!!!
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segraves1
April 2nd, 2009, 09:18 PM
Do you guys even "adjust" for altitude here in Phoenix or do you just run off the standard RDP table?
Is it reasonable to assume that provided you remain under your adjusted (for altitude) RDP table's no-deco limits throughout the day, you could make as many dives as you wanted?
Ex: When I go to the lake Saturday, provided I have surface intervals, account for residual Nitrogen, and adjust repeat dives accordingly.....I COULD just keep diving all day long right?
stnichols
April 2nd, 2009, 09:49 PM
I think you'll find that 98% of everyone here is probably using a computer which would adjust automaticly. To be honest its been such a long time since I have used tables it would probably take a very long surface interval for me to figure out my group
Rudebob
April 2nd, 2009, 10:07 PM
Well you ask a lot of good questions. The problem is there is the "safe" answer and then there is a practical or reasonable answer. Nobody is going to advise you to continue numerous repetitive dives within the same days just becasuse you keep your nitrogen load in check. Fatigue, physical and mental conditioning and a whole host of other factors will affect several different people in several different ways. On the other hand 3 or 4 dives in a day at 1500 ft can be done, IMO, safely if one knows and stays within their limits.
Sure you can adjust your RDP to compensate for the altitude. If you want to get even more technical you can factor in for fresh vs. salt water. Within the limits of a square profile based on your RDP you already most likely will have an extra saftey factor built in. Personally, I would be more concerned about the effects of water temperature and physical conditioning than that of 1500' altitude. That is just my opinion others may disagree.
mg
ScubaSteve2000
April 2nd, 2009, 11:28 PM
After reading these great posts I realize that my answer was somewhat simplistic. But then, so am I. I've done 4 dives at the lake on a few occasions. Makes the drive home really long because I'm trying to stay awake. That's why I usually keep it to three dives.
RAWalker
April 3rd, 2009, 01:13 AM
Chris,
You are asking some very good questions and based on the training materials for the Altitude Diver specialty you are correct in stating there is a 2 dive limit that divers should be aware of. Yes, Lake Pleasant is at aproximately 1720 feet so when diving there we should be planning our dives as if it was at 2000'. There is a formula and tables for adjusting the depth for altitude. As others have stated most of us use computers that either automatically adjust of can be set for altitude. At altitude these computers are more conservative. As you have noted many of us ignore the 2 dive limit. This is done at our own risk based on knowing our own limits, and conditions. Generally we do not get anywhere near our nitrogen limits and we use extended surface intervals. The fact that although 1700 is an altitude dive it really isn't so far above sea level compared to the recreation limit of 10,000 feet above sea level so many of us just ignore the 2 dive limit.
scubajcf
April 3rd, 2009, 09:31 AM
Do you guys even "adjust" for altitude here in Phoenix or do you just run off the standard RDP table?
Lake Pleasant is a 2000 foot altitude dive. Use your theoretical depth chart when planning dives at LP using the RDP. If you are using a computer, make sure it is set for altititude. My advice: use the tables properly.
Is it reasonable to assume that provided you remain under your adjusted (for altitude) RDP table's no-deco limits throughout the day, you could make as many dives as you wanted?
Recommendations like # of dives, depth limits, penetration rules, etc. are made by agencies for your safety. Yes, they are conservative. There are no scuba cops for when you violate these recommendations. However, when/if you do, now you are taking responsibility for making that decision knowing that someone smarter than all of us probably thinks it is a bad idea.
Ex: When I go to the lake Saturday, provided I have surface intervals, account for residual Nitrogen, and adjust repeat dives accordingly.....I COULD just keep diving all day long right?
You could also fall into a category for an "undeserved hit" as well.
....
In reading over your question, I feel like you are probing to see if it is "ok" or "safe" to exceed the recommended limits. No one is going to give you that answer, because as I said above, exceeding limits is about "you taking responsibility". If you are still questioning the decision, I would suggest you stay within the limits. Continue your training, continue practicing, and continue asking great questions like this and your knowledge base will continue to flourish. Then you can make educated decisions and understand potential ramifications.
It's passion like this that makes a great diver - divemaster - instructor!
Fatigue, physical and mental conditioning and a whole host of other factors will affect several different people in several different ways.
Great point Mike!
jcf
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AZTEK DIVER
April 3rd, 2009, 08:53 PM
This is pretty funny, you got John F. on here telling you about 2 dives a day and how smart the training agencies are, but he posts on his blog about doing 6 dives in a day at LP, do as he says, not as he does. Your info says your from Fountain Hills which is about the same altitude as LP, so your body is already acclimated to this pressure, which DOES make a difference. As long as you stay within your tables you should be fine, adding nitrox can make the ride home a little more open eyed. Undeserved hits are mostly just an excuse to explain away the fact that you screwed up, are way too fat and out of shape, have a PFO, or just don't have a clue what you're doing. Have a great weekend of diving.
Dive-aholic
April 4th, 2009, 02:23 AM
I've done several dives a day at Pleasant, including 3 training dives a day. The 2 dive limit is a recommendation, not a set standard. PADI does allow 3 training dives at altitude. Look at the table, there is not much of a difference in the depth when adjusting for the 2000' level. And my guess is most, if not all, of your Lake Pleasant dives are shallower than 60'. The adjustment is next to nothing. Head down to Patagonia and you should probably limit yourself to 2 dives a day. But at Pleasant, you should be find doing however many dives you want, especially since you live at the same elevation. Like John Sampson said, "Have a great weekend of diving."
Walter
April 4th, 2009, 07:08 AM
The NOAA Diving Manual states, "Repetitive dives may be conducted at altitude. The procedure is identical to that at sea level, with the exception that the sea level equivalent dive depth is always used to replace the actual dive depth."
scubajcf
April 5th, 2009, 01:52 AM
This is pretty funny, you got John F. on here telling you about 2 dives a day and how smart the training agencies are, but he posts on his blog about doing 6 dives in a day at LP, do as he says, not as he does.
Hi John, I'd like to thank you for pointing out the conflict between my blog where I state we (as a group) did six dives in a day. We were out there all day and yes, we did six dives. I participated in three of them. Two of them we were practicing rescue diver skills which, as you know, tend to be shallow and short. However, should I have chosen to do more, I would be responsible for my own profile. Which was my point being made.
Yes, as a whole, I do think the training agencies are very bright when it comes to dive education information and putting together recommendations for the general diving population. I am certainly not going to say I don't disagree with them from time to time and perhaps, armed with some experience and knowledge, exceed them.
Lastly, I tend to advise new divers (such as the OP) follow agency guidelines and recommendations. Especially when I don't know them well enough to recommend something less conservative (as would be the case with the OP).
