Diving to 130 ft ?

[Mike]

My wife and I have roughly 45 dives each over the course of about 7 years of recreational vacation diving.

100ft is the deepest we have dived, with many logged dives to 80.

We are comfortable with diving but I'm wondering what the thoughts are in regard to going to 130ft for the first time.

The reason I ask is we will be diving in Cozumel this Thanksgiving and have plans of doing Punta Sur which goes to 130 ft.

I've never been able to detect any narcosis but I'm a little concerned about a 30% jump in diving depth.

I don't see any opportunity to go deeper incrementally at this point.

 

[Doc]

Find a reason to go to whatever particular depth before you decide to go there.

If you are just going to 130' just to log that fact, this I can not help you with.

Not much down there to see.

Narcosis and recognizing the symptoms has been bandied about since the beginning of recreational diving. On Scuba Board, too.

 

[gcbryan]

There's not really an answer to your question. You want to do a dive to 130fsw and you can't dive shallow first. So you either dive to 130fsw or you don't.

The bottom goes to 130fsw...is there nothing to see shallower than that? Are there no shallower dives that you will be doing on vacation before the 130fsw dive? How many dives will you be doing on your vacation? You should be able to stay well of the bottom for a least some of them to see how the greater depth affects you.

 

[divechk]

I presume you will be on an AL 80. Can't stay down at 130 very long if on an AL 80. You might enjoy a more leisurely dive if you stay shallower. I'm not sure if it would be worth it for a few minutes.

Also, since you are not familiar with the dive site, having gone that deep, narcosis and etc, you might suck up more gas than you would normally do. Again, your burn rate for gas will be higher as at depth the air you breathe is more condensed due to pressure. Also, what if someone panics at depth? You'll need reserve air for buddy too.

If you do it, consider nitrox, as you'll be one letter class lower on the dive charts.

 

[ScubaDocER]

I just returned from Cozumel in April and had a GREAT time as usual. To answer your question, I would say that your dive to 130 ft (if you choose to do it) should be well planned with the consequences well understood. Be aware of the increased risk of narcosis as well as the additional nitrogen you will be absorbing. Be aware that you will use air faster than you normally would when not diving to 130 ft. Be aware that you will be diving in current and that if you were to incur a decompression obligation then you may need a SMB to complete your decompression safely as well as the gas to actually complete the deco stop. You did not mention your level of training, but they have Nitrox available in most places, which you might want to consider.

Diving to 130 feet is not necessarily a difficult thing to do. It does however require more detailed planning and preparation, including emergency procedures in case you become lost or separated. The concern you have in making the jump to dive to 130 is justified and should give you pause. I was given the option to do a similar dive in Cozumel and passed. There were plenty of things to see at 100 feet and I enjoyed every moment of it.

 

[Mike]

This is the description of the dive, it' my understanding the normal dive is to drop to 90, enter the cavern, exit at 130.

Punta Sur Deep
Depth: 90 to 130 feet
Skill level: Advanced
This is diving for the experienced at it's best. Home to the famous "Devil's Throat" which starts at the opening of a dark narrow tunnel at 90 feet and takes you out into a sunlite opening at 130 feet on the wall. Eagle rays and sharks are occasionally spoted here. Other spots include the cathedral, which is a large cave opening with giant sponges that form a cross in the ceiling of the cave where light passes through.
Incredible pinnacles of coral, very dramatic
drop-off, watch for turtles, rays & sharks.
Currents can be strong & unpredictable.
PUNTA SUR is the home of the widely acclaimed DEVIL'S THROAT with incredible topography and huge caverns. The entrance to the Caves is at 135 feet which exits at 90 feet or vice-a-versa. Bring a dive light for this one. ( Advanced )​

 

[Mike]

There's not really an answer to your question. You want to do a dive to 130fsw and you can't dive shallow first. So you either dive to 130fsw or you don't.

The bottom goes to 130fsw...is there nothing to see shallower than that? Are there no shallower dives that you will be doing on vacation before the 130fsw dive? How many dives will you be doing on your vacation? You should be able to stay well of the bottom for a least some of them to see how the greater depth affects you.

The majority of coz dives are 80 ft or less. 25 dives there and my log shows never below 85 ft. Like I said no real opportunity that I think of doing anything incremental while I'm there and then do Punta Sur.

I'm nervous about the effects of being narc'd for the first time in a combination of an advanced dive situation.

Might be smarter to avoid this one until we get a chance to do some slightly deeper dives gradually and be able to monitor our reactons.

 

[vixtor]

To do your first 40m (135 feet) dive in strong current in a cavern seems to me that you are pushing it too much. What is your cave/cavern experience before this dive?

 

[TSandM]

If you do it, consider nitrox, as you'll be one letter class lower on the dive charts.

130 feet would be 28% Nitrox at max, if you're going to respect the 1.4 ATA MOD. At least when we were in Coz, you didn't have an option of custom Nitrox mixes, and we got 32% routinely.

As has already been stated, there are a number of considerations when you are going to expand your environment into the deep recreational range. Narcosis is one, and personally, I think that doing a long, light-limited swim-through, with options for taking a wrong turn (and there are such options there), when untrained in overhead environments and at a depth where narcosis is going to play a definite role, is an unwise tack. I know a lot of people do this dive and enjoy it, but having read the story of a man whose wife panicked and tried to bolt up a crack that didn't actually permit her to get out (she ended up getting CPR, and survived) I had no real desire to do that dive. We kept to 100 feet or shallower and had plenty of fun.

Another consideration is gas reserves. There is no question that you can go to 130 feet on an 80 cubic foot tank and get back up -- but what if your buddy runs out of gas there? Do you have enough reserve to get you AND your buddy back up to the surface, at a safe ascent rate?

Time at those depths is quite limited; no deco time at 130 feet is going to be in the ten minute or less range, depending on the decompression model you are using, and your gas supply may not even permit that much time there, unless the dive is essentially a bounce.

One of my most respected ScubaBoard role models, Mike Ferrara, said a long time ago that such dives are better done as proper staged decompression dives, with the right equipment and the right training, and I agree with him.

 

[MXGratefulDiver]

My wife and I have roughly 45 dives each over the course of about 7 years of recreational vacation diving.

100ft is the deepest we have dived, with many logged dives to 80.

We are comfortable with diving but I'm wondering what the thoughts are in regard to going to 130ft for the first time.

The reason I ask is we will be diving in Cozumel this Thanksgiving and have plans of doing Punta Sur which goes to 130 ft.

I've never been able to detect any narcosis but I'm a little concerned about a 30% jump in diving depth.

I don't see any opportunity to go deeper incrementally at this point.

I wrote an article for folks like you ... it may answer your questions and give you things to consider that you haven't yet.

When I was in Cozumel, my group decided to pass up that dive ... primarily because we felt we'd get more value out of a longer, shallower dive that was more suitable to our goals and the equipment we were using. And I think, in hindsight, that was a good decision.

Narcosis is certainly a good consideration ... but a more important one is how quickly will you go through your air supply, and what will you do if one or both of you get to unacceptly low reserves while you're inside that swimthrough?

What size cylinder will you be using? If AL80's, then count on it being a very short dive ... do "trophy" dives appeal to you? If not, then opt for a shallower, longer dive. There are plenty of those to be had that will give you more bang for the buck.

Also, will you be using your own or rental regs? Personally I would never take a rental reg to 130 fsw ... because you don't know when it was serviced last or how well it will perform at that depth. Cheaper regs that are commonly used for rentals regs tend to perform less well at deeper depths ... and increased work of breathing leads to CO2 buildup in your bloodstream ... which will lead to an unpleasant (at best) feeling like you can't get enough air. That tends to stress people out ... and even if you don't normally feel the effects of narcosis, CO2 and stress will help you feel it at deeper depths.

Read the article, weigh your options, and make an informed decision ... only you, really, can determine what's important to you. But if you DO decide to go ... keep a close eye on your pressure gauge. You'd be surprised how quickly it can go down when you're in any new environment ... much less one at that depth.

... Bob (Grateful Diver)