Any Tips on Conserving Air?

[Dive Hawk]

If you are comfortable in the water, and you DO have good buoyancy control, then my recommendation is to not worry about it. Your air consumption is what it is, and efforts to artificially lower it are a bad idea.

I feel relatively comfortable underwater, but I feel natural sitting here typing on my computer which is why I use the term relatively.

I haven't run into anything which causes anything more than slight anxiety: going through "caves" in Shark's Cove on Oahu, which are really more like swim-throughs. The reasoning being it was foreign or "alien" to me since I learned how to dive in an open, empty lake, and going through areas of mostly black are just that, "alien."

As for buoyancy, I am getting better, but I really noticed on my last dive to the Sea Tiger that if I stopped finning, I sank like a rock. I think dropping a few pounds of weight and learning how to control my BCD better would help significantly, as you say.

So to sum up all the responses; once I slow everything down, and once diving becomes like second nature to me, and once I learn how to effectively and efficiently control my buoyancy and finning, I should breathe a bit better. Did I mention I likely need to slow down!? :cool2:

Thanks for all the quick responses!

 

[Splitlip]

Oh yeah. And what RJP said.

Oh, steady and slow.

 

[Dive Hawk]

@Splitlip -- I love that signature. I can hear the deep voice the original words are narrated in, but I can't place it. Was it originally from a beer commercial or maybe a truck commercial? It's driving me nuts that I can't place it! :errrr:

 

[Charlie99]

As for buoyancy, I am getting better, but I really noticed on my last dive to the Sea Tiger that if I stopped finning, I sank like a rock. I think dropping a few pounds of weight and learning how to control my BCD better would help significantly, as you say.

That sinking if you stop is exactly what I was describing. The problem isn't a few extra pounds of lead, it's too little air in your BCD.

There's a difference between being overweighted and being negatively buoyant. Even a diver that is perfectly weighted will be significantly negatively buoyant at depth if he doesn't add enough air to the BCD. That's because your wetsuit compresses. And at the beginning of your dive, you will have the extra weight of the air in your tank (6 pounds for an AL80).

You should make it a habit to stop finning every minute or so, and definitely when you change depths, and see if you sink.

A lot of divers are nervous about putting enough air into their bcd because they fear runaway ascents. A good antidote for that fear is to do a deep water hover with your lung cycle breathing in and out near full. Keep adding air to the bcd until you are truly neutral or even a bit positive buoyant. Then exhale strongly and see how quickly you sink. Once you have that ingrained reaction of "exhale strongly to stop an ascent", then you will feel a lot more comfortable getting truly neutral.

 

[Dive Hawk]

That sinking if you stop is exactly what I was describing. The problem isn't a few extra pounds of lead, it's too little air in your BCD.

There's a difference between being overweighted and being negatively buoyant. Even a diver that is perfectly weighted will be significantly negatively buoyant at depth if he doesn't add enough air to the BCD. That's because your wetsuit compresses. And at the beginning of your dive, you will have the extra weight of the air in your tank (6 pounds for an AL80).

You should make it a habit to stop finning every minute or so, and definitely when you change depths, and see if you sink.

A lot of divers are nervous about putting enough air into their bcd because they fear runaway ascents. A good antidote for that fear is to do a deep water hover with your lung cycle breathing in and out near full. Keep adding air to the bcd until you are truly neutral or even a bit positive buoyant. Then exhale strongly and see how quickly you sink. Once you have that ingrained reaction of "exhale strongly to stop an ascent", then you will feel a lot more comfortable getting truly neutral.

That makes perfect sense to me. I don't necessarily fear runaway ascents, though I do consider them a possibility. The real problem for me is not actively using the BCD until I realize, "Wow, I'm putting in way too much effort to stay level, I should probably add some air to my BCD." Then, it's difficult to say how much you should actually add, etc., etc., but I know that to be lack of experience, especially experience at greater depths.

As for weight, I know I'm overweighted because I've been told on three separate occasions that I'm overweighted. I know what this sounds like, but I've proven it to be my suit: the Pinnacle Merino-Elastiprene 3mm. Once the suit begins to crush it sinks like any other suit I've tried, but I can't get past 15 feet with anything less than 16 lbs in that suit.

Examples: I can sink with 18 lbs in my Bare Elastek 7mm with a 7mm hood, 5mm gloves and 7mm boots. (I use 3mm boots with the Pinnacle suit). In the Bahamas, I switched to a rented 5mm suit and sank with 12 lbs wearing boots and gloves. In Hawaii, I rented a 3mm for two dives and sank with 10 lbs, although 8 lbs would have been more than enough.

The divemaster in Hawaii had no idea what the deal was, and my instructor here in Arizona said that he had similar problems with his Merino lined suit, and he sold it after 4 dives.

Anyways, I know that has nothing to do with negative buoyancy at depth, but shedding 6-8 lbs couldn't hurt.

Thanks again for the input.

 

[Bubbletrubble]

As for weight, I know I'm overweighted because I've been told on three separate occasions that I'm overweighted. I know what this sounds like, but I've proven it to be my suit: the Pinnacle Merino-Elastiprene 3mm. Once the suit begins to crush it sinks like any other suit I've tried, but I can't get past 15 feet with anything less than 16 lbs in that suit.

Examples: I can sink with 18 lbs in my Bare Elastek 7mm with a 7mm hood, 5mm gloves and 7mm boots. (I use 3mm boots with the Pinnacle suit). In the Bahamas, I switched to a rented 5mm suit and sank with 12 lbs wearing boots and gloves. In Hawaii, I rented a 3mm for two dives and sank with 10 lbs, although 8 lbs would have been more than enough.

The divemaster in Hawaii had no idea what the deal was, and my instructor here in Arizona said that he had similar problems with his Merino lined suit, and he sold it after 4 dives.

@Dive Hawk:

• Do you always do your weight checks prior to doing a dive?
• Are you 100% sure that all of the air bubbles have been worked out of your suit prior to conducting the weight check?
• Is it possible that the Merino-lined suit just takes some time to get sufficiently water-logged?
• Have you ever tried doing a weight check at the end of the dive (rather than the beginning) while using the Merino-lined suit?

Make sure that you remember to compensate for any remaining gas in your tank when determining your minimum weighting requirements during a weight check.

This is the first time I've heard that the 3mm Pinnacle Merino-Elastiprene wetsuit has more inherent positive buoyancy than a comparable 3mm non-Merino wetsuit.

 

[Dive Hawk]

@Dive Hawk:

• Do you always do your weight checks prior to doing a dive?
• Are you 100% sure that all of the air bubbles have been worked out of your suit prior to conducting the weight check?
• Is it possible that the Merino-lined suit just takes some time to get sufficiently water-logged?
• Have you ever tried doing a weight check at the end of the dive (rather than the beginning) while using the Merino-lined suit?

Make sure that you remember to compensate for any remaining gas in your tank when determining your minimum weighting requirements during a weight check.

This is the first time I've heard that the 3mm Pinnacle Merino-Elastiprene wetsuit has more inherent positive buoyancy than a comparable 3mm non-Merino wetsuit.

I only do weight checks on the first dive of each week unless I change something. I use all of the same gear all of the time, and my bodyweight doesn't fluctuate.

I have no idea if all the air bubbles have been worked out each time, but like I said, I've tested four different suits in all the common widths, and I can't say if air bubbles were an issue or not.

As for the issue of the suit being waterlogged, the divemaster in Hawaii suggested that could be an issue, but can (should!!) that issue cause a difference of 6 to 8 pounds when comparing 3mm suits?

The last question got me thinking... At the end of my 6th dive in Hawaii I believe I was slightly negative at 15 ft with an empty BC without a reference line. I was basically floating and staring at my dive computer to check depth. I should add that we were in a bit of surge, so it's hard to say whether that information is worth anything.

I've never actually done a weight check at the end of a dive in it, though, at least none that I can remember!

Edit: I'm going to ask my instructor (PADI Master Instructor) what it was about that suit that he thought made it floaty. I'm 99% sure he said that the Merino lining trapped a LOT more air than he thought it should. I'll find out soon, as I have to run into the shop tomorrow.

 

[Foxfish]

Relax. Get used to and enjoy the water. The lower your heart rate the less air you use.

 

[Bubbletrubble]

@Dive Hawk: If you were slightly negatively buoyant at 15 fsw with an empty BCD, then you would have started to descend and continued to descend...unless you inhaled deeply or added air into your BCD. Is that what happened?

I'm also getting the feeling that there might be some issues with how you're conducting your weight checks. I could be wrong, though. Are you doing the weight checks as described in your PADI OW classroom materials? (no air pockets in wetsuit, no kicking, holding normal breath, empty BCD, near empty tank, water at eye level at surface)

 

[Dive Hawk]

@Dive Hawk: If you were slightly negatively buoyant at 15 fsw with an empty BCD, then you would have started to descend and continued to descend...unless you inhaled deeply or added air into your BCD. Is that what happened?

I'm also getting the feeling that there might be some issues with how you're conducting your weight checks. I could be wrong, though. Are you doing the weight checks as described in your PADI OW classroom materials? (no air pockets in wetsuit, no kicking, holding normal breath, empty BCD, near empty tank, water at eye level at surface)

I've never done a weight check with a near empty tank, but all the other criteria are met. No one has ever asked me to do a weight check with a near empty tank, we just add 5 lbs to compensate for an empty or near empty tank.


As for being slightly negatively buoyant, I was vertical in the water, and I finned lightly during exhales after I realized I was sinking, and it was very slowly.