1st time to Cozumel need help finding a dive shop

[judydivescoz]

Joewr, remember a diver must be nitrox certified in order to use nitrox. Having "good bottom times" is not a factor at all. Its been a long time since I took the course and was certified but you suggestion if 36% for two dives and 32% for one dive confuse me. I just got back from a live aboard trip where all nitrox certified divers dove on 32% 5 dives a day all week.

Folks,

That is one of the reasons we like Mantaraya. Fernando uses the "loose buddy" system. When you need to head for the surface, up you go...and Samy is right there since he follows the bubbles...if you have good bottom times, Fernando is with you all the way...and so far, no one has been able to outlast him!:blinking:

One quick note: if you do have good bottom times, ask Fernando for Nitrox...typically, he will get 32% and 36% if you want it for both dives...32% if for only one dive...

joewr...good bottom times mean great surface intervals!

 

[Mossman]

Rubbish. I've dove Aldora for 2 trips, and buddy teams go up as they run low on air. The whole group coming up together, because one diver ran low? Never happened. I've seen some teams spend an extra 10+ minutes of bottom time while the rest of the group boards the boat.
I checked my dive log from last trip, out of ten dives, only one was less than an hour; 59 minutes. The longest was 1:16. Not bad dive times.
The HP steel tanks are sweet, well balanced and easy to dive.
Blue XTC is also an excellent op.
Maybe the "ascend together" thing happened with a group of less experienced divers.

Perhaps they've updated their policies. That's a good thing.

"It is also important to note that most of all the dives in Cozumel will be in
performed in drifting conditions. That means the group must stay together during
all parts of the dive, from descent to exit." -- Aldora Divers of Cozumel

"Only dive restriction was that we come up with at least 500 psi. We tended
to come up in a group (never more than 6 divers on the boat); if someone
was sucking air, the divemaster would feed her/him air through an octopus
with 10' hose."
Cozumel and the Mexican Yucatan Diving Review of Aldora Divers, 2007/02

" As a part of his briefing he told us that he would not send divers to the surface one at a time. When one had dived the tank limit, we would ascend as a group. "
http://www.scubaboard.com/forums/cozumel/320016-kudos-aldora-divers.html

and, of course, this entire thread:
http://www.scubaboard.com/forums/cozumel/342882-air-sharing-part-dive-plan-coz-dives.html

 

[joewr]

Joewr, remember a diver must be nitrox certified in order to use nitrox. Having "good bottom times" is not a factor at all. Its been a long time since I took the course and was certified but you suggestion if 36% for two dives and 32% for one dive confuse me. I just got back from a live aboard trip where all nitrox certified divers dove on 32% 5 dives a day all week.

Hi, Judy,

Of course, you have to be EAN certed...I assumed all would know...but as a friend used to say, "Assumption is the mother or father of all screw-ups!"

And what I meant was that for a two tank nitrox dive, Fernando offers 32% followed by 36%. That is somewhat conventional since, traditionally, your second dive is not as deep. For one tank, he normally offers 32%, but you can request 36%. And, sure, you can dive 5 dives a day on 32%...just as you can dive 5 dives a day on air...But, as you know, Nitrox will keep you out of the yellow/red better than air.

As for bottom times, I am not certain what Nitrox does for you if you do not have good bottom times. Without good bottom times, you will never go into the yellow/red. With good bottom times, Nitrox will keep you in the green whereas you could go into the yellow/red on air. And for the second dive, Nitrox is a real blessing...but, again, if you do not have good bottom times, it will not matter.

So, I do not understand why you think bottom time are irrelevant: Nitrox is all about staying out of the yellow/red and that is all about bottom time. Here is what Wikipedia says:

"Reducing the proportion of nitrogen by increasing the proportion of oxygen reduces the risk of decompression sickness for the same dive profile, or allows extended dive times without increasing the need for decompression stops for the same risk."

I interpret "extended dive times" to mean extended bottom time.

Here is what PADI (my cert agency) says:

"The most common use of nitrox mixtures containing higher than normal levels of oxygen is in scuba diving, where the reduced percentage of nitrogen is advantageous in reducing nitrogen take up in the body's tissues and so extending the possible dive time."

Again, I interprest "extending the possible dive time" to extended bottom time.

And, of course, all this means less chance of decompression disease for a given depth/time (= bottom time). Is there another reason for Nitrox?


joewr

 

[divingjd]

I dove for two weeks with Aldora in February. We generally did not have to surface early when others ran short of air. Most of the time, we were in a well-matched group and everyone tended to be ready to surface together. Other times, buddy teams were sent up together, at least when there was a divemaster intern around to accompany them to the surface. i really think they were adjusting to the group and the circumstances. The first time i dove with them, someone in the group was breathing off the divemaster's long hose so that we could all get some more time and some of use waited at fifteen feet for a long time for someone who had not monitored his computer well and incurred a deco obligation. I have seen other dive operations call dives because of a time limit or to have the group ascend together. I've had longer dives with Aldora and they seemed to be doing everything they could to get customers the dives they were promised. Their policy on keeping the group together is a statement of the PADI policy on drift diving. i don't they really have much choice on using that as the stated policy.

 

[Mossman]

Their policy on keeping the group together is a statement of the PADI policy on drift diving. i don't they really have much choice on using that as the stated policy.

Ah, maybe that's it. One more reason why I try to avoid PADI-blessed shops.

I suppose they also don't take divers below the PADI AOW "hard bottom" of 100 feet? (cough, cough)

 

[Mike]

I think putting heavy breather divers on the DMs hookah is good peer pressure to force them to learn to dive better, I've watched many a diver improve greatly in his breathing after getting tired of being the DM's bitch being dragged along under water like a party balloon.

And I have to agree diving with Aldora is a bitch, those 90 minute dives I keep logging with them aren't for everyone, tell those that get cold easy to bring a hood, cause you won't be coming up for a long time. Maybe even bring a snack down with you.

 

[Christi]

And, of course, all this means less chance of decompression disease for a given depth/time (= bottom time). Is there another reason for Nitrox?


joewr

First, I assume that your reference to "those who get good bottom times" refers to those with good air management who can get a lot of bottom time from a tank - I think that is what had a few people confused.

I am a big advocate of Nitrox and MANY of my divers use it because we allow our divers to dive their air and computers. We have a large percentage of our divers who can routinely get 70 - 80 minutes out of an AL 80 with a well managed profile in regards to NDL's. I personally only dive nitrox when I dive.

However, this last statement by you is inaccurate and can be very misleading to people who are not nitrox certified or who do not truly understand the benefits of nitrox.


The truth is that if you push the limits on nitrox, meaning if you dive nitrox beyond air NDL's up to the nitrox NDL's there is absolutely no difference than diving air to the air NDL's. However, if you dive nitrox while respecting your air limits, you are logically following a more conservative plan, but there still is no proof that nitrox reduces the chances of DCS.

 

[joewr]

First, I assume that your reference to "those who get good bottom times" refers to those with good air management who can get a lot of bottom time from a tank - I think that is what had a few people confused.

I am a big advocate of Nitrox and MANY of my divers use it because we allow our divers to dive their air and computers. We have a large percentage of our divers who can routinely get 70 - 80 minutes out of an AL 80 with a well managed profile in regards to NDL's. I personally only dive nitrox when I dive.

However, this last statement by you is inaccurate and can be very misleading to people who are not nitrox certified or who do not truly understand the benefits of nitrox.


The truth is that if you push the limits on nitrox, meaning if you dive nitrox beyond air NDL's up to the nitrox NDL's there is absolutely no difference than diving air to the air NDL's. However, if you dive nitrox while respecting your air limits, you are logically following a more conservative plan, but there still is no proof that nitrox reduces the chances of DCS.

Hi, Christie,

I guess I am just an old diver with with old lingo. To me "bottom times" always meant how long one was UW. Our typical dives off Cozumel are around 60-80 minutes, depending on depth and, so, Nitrox works very well in keeping us out of the yellow/red. I carry two dive computers (consol Genesis and wrist Suunto Stinger--yes, I am that old!) and (as an experiment) have dived Nitrox with one set to air and one set to my EAN blend. Inevitably, the air-set computer goes into the yellow or red; this is especially true on the second dive.

If my statement was misleading because it made a non-Nitrox-certed diver think that it will improve his/her air management skills, mea culpa. I sure did not mean that.

I guess, I keep wanting to hear what the reason for using Nitrox is if not avoiding DCS issues for long dives (or, in my ancient parlance, long "bottom times"). Hey...long, wonderfully scenic live boat drift dives are, for us, what Cozumel is all about.:blinking:

joewr...no messages here today...

 

[cvchief]

First, I assume that your reference to "those who get good bottom times" refers to those with good air management who can get a lot of bottom time from a tank - I think that is what had a few people confused.

I am a big advocate of Nitrox and MANY of my divers use it because we allow our divers to dive their air and computers. We have a large percentage of our divers who can routinely get 70 - 80 minutes out of an AL 80 with a well managed profile in regards to NDL's. I personally only dive nitrox when I dive.

However, this last statement by you is inaccurate and can be very misleading to people who are not nitrox certified or who do not truly understand the benefits of nitrox.


The truth is that if you push the limits on nitrox, meaning if you dive nitrox beyond air NDL's up to the nitrox NDL's there is absolutely no difference than diving air to the air NDL's. However, if you dive nitrox while respecting your air limits, you are logically following a more conservative plan, but there still is no proof that nitrox reduces the chances of DCS.

Correct me if I am wrong, but if you have a 60 minutes at 60 feet on air, you will load more nitrogen that if the same dive or 60 minutes at 60 feet on nitrox, right? So reduced nitrogen load = a protective effect.

Or you can use Nitrox to get a longer 'safe' bottom time and NO extra protective effect, right?

Alert Diver | DAN Medics Answer Your Questions about Dive Medicine: Spring 2011

 

[sharky60]

Most dive ops have rental equipment available and will quote it into the price if requested.

Top 5 recos: (in Alpha order),

1.) Aldora Divers - top notch dive operation, used and recommended by many here on the SB

2.) Blue Angel - fast boats with recently updated motors, very good DM's & captains, excellent on site instructor, slightly lower rates than most.

3.) BlueXTSea - "boutique" diving at it's best, a little extra cost gives you extra pampering and service. superbly managed operation.

4.) Bottom time Divers - small, one-man operation, Raul is an excellent DM, very safety minded and super good at finding critters

5.) Dive with Martin - some of the lowest rates on the island, (cash only), excellent DM's and captains, fast boats, good guys. long time island favorite.

all these dive ops will pick up and drop you off back at your hotel pier.