Cozumel dive ops with hp119s or hp120s?

[Ron Lee]

Dear Mossman,
Yes, you can have your money back, or replacement diving. Just tell me which you prefer by PM.

Amazing.

 

[MMM]

According to their web site, Living Underwater uses LP tanks, not HP. That could make a significant difference, depending upon how much they are filled. Can anyone who has used that operator report on the customary level of the fills?

. I just checked my computer for past 6 dives and it says my starting pressure on each was 2551, 2346, 2466, 2507, 2405, and 2583. I'm not the sharpest knife in the drawer when it comes to math but I think that works out to an average of just over 2476 lbs. (feel free to correct me since I did it all longhand!) Jeremy tells anyone freaking out on the boat that 2400 lbs is a "full" tank.

 

[Tunaman68]

Blue Angel has AL100's available for an extra $5 - they use AL80's as standard so that gives a little leeway for the gas challenged.

 

[boulderjohn]

. I just checked my computer for past 6 dives and it says my starting pressure on each was 2551, 2346, 2466, 2507, 2405, and 2583. I'm not the sharpest knife in the drawer when it comes to math but I think that works out to an average of just over 2476 lbs. (feel free to correct me since I did it all longhand!) Jeremy tells anyone freaking out on the boat that 2400 lbs is a "full" tank.

It sounds as if the tanks were generally filled at the standard fill pressure, so you are getting what is advertised.

For reasons that never made sense to me, these tanks have a normal fill pressure of 2400, so he is technically correct. However, they also normally have a +10% rating, meaning that the tank is not really full until it is at 2640. An LP 120 filled to 2640 has 120 cubic feet of gas. An HP 120 filled to 3450 has 120 cubic feet of gas.

In a lot of places, you will see LP tanks filled to 3,000 PSI, in which case you are getting more than an advertised fill. If you go to cave country in Florida, LP tanks are routinely filled to 3600 PSI or higher.

 

[MMM]

It sounds as if the tanks were generally filled at the standard fill pressure, so you are getting what is advertised.

For reasons that never made sense to me, these tanks have a normal fill pressure of 2400, so he is technically correct. However, they also normally have a +10% rating, meaning that the tank is not really full until it is at 2640. An LP 120 filled to 2640 has 120 cubic feet of gas. An HP 120 filled to 3450 has 120 cubic feet of gas.

In a lot of places, you will see LP tanks filled to 3,000 PSI, in which case you are getting more than an advertised fill. If you go to cave country in Florida, LP tanks are routinely filled to 3600 PSI or higher.

Yes, he used to fill them much higher than he does now but years ago someone made an issue out of it in a fairly public forum. Undercurrent, I think, which is where he gets a lot of new clientele. He bowed to the pressure and has been filling to the technically approved limit since then.

 

[Pelagicsal]

So, in regard to the big-tank ops, if a diver is with a group that can make good use of that much air (or Nitrox), does it mess up the boat schedule/unduly bore the divemaster if everyone wants to stay down, say, 90+ minutes? Or are those kinds of times built into the schedule?

Often when everyone wants and can stay 90+ minutes, the DM is having a great time diving with very good divers. At least that has been my experience with Aldora. If there's an afternoon dive, those same folks often like to go, too, so the schedule adjusts - when there are afternoon dives.

My understanding of Aldora's old policy of no regularly-scheduled afternoon dives was established with those long morning dives in mind.

If I am wrong, I am sure Dave will pop up and chastise me roundly!

 

[boulderjohn]

Blue Angel has AL100's available for an extra $5 - they use AL80's as standard so that gives a little leeway for the gas challenged.

But as per a recent thread, not as much as you might think.

In that other thread, it was revealed that the standard fill operation on Cozumel will not fill AL tanks beyond 3,000 PSI. AL 100s have a standard fill pressure of 3300. That means they do not have 100 cubic feet unless they are filled to 3300. If they are filled to 3,000, then you will have more than an AL 80 filled to 3000, but not as much more as you think.

 

[caseybird]

A HP 120 is the same diameter and a little longer than an AL80. An AL 100 has a larger diameter. A steel 120 is one sweet tank, it sits lower on my back and doesn't tend to roll me so much. An AL 100, not so good. Plus the steel 120 has better bouyancy characteristics.
With the cost of the vacation, I want the extra dive time the steel tank gives. On my last two trips, the shortest dive was 59 minutes, and I could have stayed down longer. Well worth any extra cost.
At this point, I won't bother diving with an op without steel tanks. I wish a few other ops I really like would adopt them.

 

[Dave Dillehay]

Dear Ms. Ann Thorpe,

The reason that Aldora requires the dive group to come up together is totally for the safety of the divers. If you may recall the dive sites are also the high speed routes of dive boats going north and south. When we started Aldora Divers in 1992 the primary cause of serious accidents was divers being hit by oncoming boats whose captains were either not paying attention or drunk. Surely you have heard of divers coming up by themselves and being alone for long periods of time, hurt , or worse.

Well, we don't do that. But we do out best to keep everyone safe by staying with out group, and sharing air with the DM when possible, and letting everyone enjoy a long, safe dive.

We decided then that we would keep the groups together under the umbrella of the Dm's inflatable marker. INdeed, our operation manual calls for the captains to find our DM's marker after 45 minutes into the dive then provide a foil against oncoming boats. BUt given that our DMs are required to share air with those lower on air, and we try so hard to plan dives with that in mind, we do offer much longer dives.

However, if you demand to go up by yourself, when you want, then Aldora is not the dive op for you.

BTW, Aldora NEVER sets the dive time or site selection on getting bak for afternoon dives which we RARELY do.


Dave Dillehay
Aldora Divers

 

[DeepSeaDan]

Dear Ms. Ann Thorpe,

The reason that Aldora requires the dive group to come up together is totally for the safety of the divers. If you may recall the dive sites are also the high speed routes of dive boats going north and south. When we started Aldora Divers in 1992 the primary cause of serious accidents was divers being hit by oncoming boats whose captains were either not paying attention or drunk. Surely you have heard of divers coming up by themselves and being alone for long periods of time, hurt , or worse.

Well, we don't do that. But we do out best to keep everyone safe by staying with out group, and sharing air with the DM when possible, and letting everyone enjoy a long, safe dive.

We decided then that we would keep the groups together under the umbrella of the Dm's inflatable marker. INdeed, our operation manual calls for the captains to find our DM's marker after 45 minutes into the dive then provide a foil against oncoming boats. BUt given that our DMs are required to share air with those lower on air, and we try so hard to plan dives with that in mind, we do offer much longer dives.

However, if you demand to go up by yourself, when you want, then Aldora is not the dive op for you.

BTW, Aldora NEVER sets the dive time or site selection on getting bak for afternoon dives which we RARELY do.


Dave Dillehay
Aldora Divers

The more I read "Dave Dillehay", the more I'm convinced he must be a... Canadian!

Looking forward to diving with Aldora come April, Dave.

Regards,
DSD