Cause of high consumption rate

[Nemrod]

I added huge off road tires to my pick up truck recently... AND all of a sudden my mpg drops a lot. Do you think it MIGHT have anything to do with the tires?

I went from 35s to 33s and picked up nearly 2 MPG on the Jeep. It did not like the 35s.

Why would somebody dive dry in water warm enough for a rash guard/swimsuit on a sport dive with a single tank and no planned overhead beats me. I see it from time to time, even saw it in Cozumel. The drysuit guy went through his air supply like a Shop Vac but then even when he was not in his drysuit he went through his air like a Shop Vac. But, he was sure to let all know of his technical diving prowess.

Just like the rednecks 'roun'hea think big tires attract girls to their pu trucks, apparently some divers think the same way about a dry suit.

As to the size of the tires, I have noticed no difference in my attractiveness to the opposite sex despite the tire size reduction. But then, I have always been challenged in that department anyways, good thing I have a great personality. Maybe if I had a drysuit it would help me out there?

LOL.

When one uses every weight in the bucket to sink one's drysuit leaving none for anybody else, then that person is not popular.

N

 

[Kronek]

and for cold water, I still like the semi dry better for most recreational divers...

LOL. What is "cold water" to you Florida man? 70*F? Come talk to me when you can pull 3 dives a day in a semi dry in 33*f water, -20*f air and we can talk. Fact of the matter is, drysuits are not hard to dive. I got mine 7 dives into my career and jumped in shallow water and figured it out. I get it, you are afraid of drysuits, no problem. But please stop the warm water rhetoric.

 

[danvolker]

LOL. What is "cold water" to you Florida man? 70*F? Come talk to me when you can pull 3 dives a day in a semi dry in 33*f water, -20*f air and we can talk. Fact of the matter is, drysuits are not hard to dive. I got mine 7 dives into my career and jumped in shallow water and figured it out. I get it, you are afraid of drysuits, no problem. But please stop the warm water rhetoric.

Kronek,
First dive I did in a drysuit was a 95 foot dive....the next was to 280 feet, and I did several hundred of these. On our tech dives in Florida, even in summer, there can be a thermocline at 150 to 200, and the reef or wreck on the bottom is often 50 degrees F.

Tech divers need to use drysuits....This thread was not about tech divers though...and it was not even about how supposedly challenging it is to be in cold water ( Which I find ridiculous--my first year of diving included diving under the ice in Lake Erie..this was very easy diving--just not particularly FUN diving). And this thread is not about me, even though you felt the need to trash Florida divers.

This thread is about how the OP might be able to fix a bad SAC rate...and how a Drysuit could relate to this.


So if I have to use a Drysuit, it is very easy for me use one....My complaints about them are about things that you have not been diving long enough to even pick up on yet...maybe after another 1000 dives( with some in wetsuits), you will have had enough experiences to realize there are drag issues to drysuits.

 

[TSandM]

I dive a dry suit in warm water because I get COLD, and also because, if I'm going to do 4 dives in a day, I'd much rather slip into a dry suit four times, than struggle into a wet, chilly, uncooperative, thick wetsuit four times. I have done things both ways, and I know which I prefer. I do not see any difference between gas consumption in a wetsuit or in a dry suit, in the same water conditions. But I am very familiar with a dry suit, and I do not move fast when I dive. I will absolutely admit that there are drag differences -- they are quite noticeable when you are trying to keep a team together on scooters, just as the difference between doubles and a single tank is noticeable. But I have never in my life swum as fast as a scooter pulls me, nor do I intend to try.

 

[Nemrod]

I dive a dry suit in warm water because I get COLD, and also because, if I'm going to do 4 dives in a day, I'd much rather slip into a dry suit four times, than struggle into a wet, chilly, uncooperative, thick wetsuit four times. I have done things both ways, and I know which I prefer. I do not see any difference between gas consumption in a wetsuit or in a dry suit, in the same water conditions. But I am very familiar with a dry suit, and I do not move fast when I dive. I will absolutely admit that there are drag differences -- they are quite noticeable when you are trying to keep a team together on scooters, just as the difference between doubles and a single tank is noticeable. But I have never in my life swum as fast as a scooter pulls me, nor do I intend to try.

Maybe y'all did not fully read the OPs post where he said 30 C which is 86 F. I am sorry, but, I am just going to say that a dry suit in 86 degree water, that is a bit different and not needed, in fact, nothing is needed much less a drysuit. But, if it is 76 F, yeah, about dive number three I will be wanting my drysuit. But, I think, I get cold easy, but unless a person has some type of physical issue, 86 degrees is not likely to make them cold even after four dives.

But, if you are overhead/deco and or on a rebreather for six hours, yeah, totally with you. I do not think that is the OP and my answers where in relation to that. He would do better to ditch the drysuit in 86 degrees water.

And as to SAC air consumption being the same, wet or dry, maybe, if you are as still as a stone, I guess it would not matter, if one is active, then it does.

It does not matter how fast you intend to go if the current is going faster. Hopefully it is going where you want to go, otherwise, welcome to fluid dynamics. That anchor line into the ripping current is what it is if you must swim down it.

If minimalism is at the heart of some of these "philosophies" that are common aboard scubaboard then if equipment including exposure protection is in excess of what is actually needed for the environment, that is a complication, not a reduction in complexity. A drysuit is not minimalism for sport diving in 86 degree F water. No way.

Just a reminder, here is the OP's question and predicament:

Went for a dive trip recently and noticed that I'm sucking air faster than most everyone else on board the boat. I go down later, and have to surface earlier.


It's diving in 30 degree C waters, so other divers were wearing either 3mm wetsuits, or just rash guards with shorts. Typically divers like this carry anything from 0 to 4 pounds of weights, some 6 pounds. I was in a drysuit and carrying 12 pounds.



Am wondering if my increased consumption was due to the drysuit and extra weights? Or my shorter/fatter UTD fins?

N

 

[Storker]

I'd much rather slip into a dry suit four times, than struggle into a wet, chilly, uncooperative, thick wetsuit four times.

It doesn't even have to be four dives.

Location: Coast of Norway
Conditions: Sun, light breeze, ~13C air, ~11C water, i.e. a nice day sometime in late spring/early summer
Actors: Two dry suit divers, two semidry divers
Props: One open boat, 18' long, four sets of gear, two tanks per diver.
Scene 1: Boat gets loaded, dry suit divers suit up, semidry divers load suits, hot tea, towels & other stuff, put on life-vests.
Scene 2: Dry suit divers surface nice & toasty, semidry divers surface feeling chilly. Dry suit divers sit back and enjoy sun, wet suit divers strip off suits, starts shivering, towel off vigorously, put on clothes and life-vests, get handed hot tea and try to get warm.
Interlude: Dry suit diver #1 realises he had a little too much tea, steers boat to small island to peel off suit and pee without dripping on suit bunched between legs.
Scene 3: Semidry divers undress, put on wet and cold suits, kit up and enter water. Dry suit divers kit up and enter water.
Scene 4: Repeat scene 2. Except thermos is now empty.

Personally, I'll take the hassle of peeing without dripping on my suit over being so cold I have to sit down to pee or let it go inside the wetsuit...



--
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Typos are a feature, not a bug

 

[Nemrod]

Just an observation about human nature, to internalize a circumstance. This commonly occurs in these forums and people start ancedotal-yzing. The thread is not about diving in Norway in 11C water. It is about diving in 86 degree (30C) water. The thread is about the OP, to help the OP, not discuss diving dry vs wet, to help him/her lower their air consumption to equal that of his/her buddies.

N

 

[TSandM]

Well, the second trip I did to the Red Sea, I took my dry suit. We were diving in the south, in water that ranged from 84 to 86. I was talked out of the dry suit and into a wetsuit for ONE dive -- and about 30 minutes into it, I thought, "I'm chilly! Why did I do this?" I went back to the dry suit for the rest of the trip. Whether or not you get that cold in such warm water (and we were doing a lot of 90 minute dives), the ease of getting in and out of a dry suit multiple times a day would sell me.

 

[Storker]

The thread is about the OP, to help the OP, not discuss diving dry vs wet

Having been here for only about a year, I'm still trying to find out how far it's acceptable to veer from the original topic on this forum, but I think I'm starting to get it now:

When an OP asks whether his dry suit can be the cause for his increased SAC, "ditch the drysuit" or "drysuits are bad for diving skills" are acceptable and ontopic, while "drysuits aren't difficult to master" or anecdotes that try to make the tone lighter are offtopic. Am I right?



--
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Typos are a feature, not a bug

 

[WhiteSands]

I tried this too and it did not work out for me, as I recognized I was taking a deeper breath to inflate my BCD so I returned to using the inflator but press it only a tiny little bit to let as little air in as necessary breathng comfortably all through the action.

Try using only the air that you're going to exhale out into the reg anyway. That way you are "recycling" the waste air, and not consuming air to inflate the BCD.

I orally inflate before jumping off the boat too. Trying to be a real scrooge with air to extend my bottom time.

---------- Post added December 24th, 2013 at 11:23 AM ----------

Hi WhiteSands,


You haven't said which type of dry-suit your using membrane or neoprene?

It's a trilam suit.

---------- Post added December 24th, 2013 at 11:25 AM ----------

I went from 35s to 33s and picked up nearly 2 MPG on the Jeep. It did not like the 35s.

Why would somebody dive dry in water warm enough for a rash guard/swimsuit on a sport dive with a single tank and no planned overhead beats me. I see it from time to time, even saw it in Cozumel. The drysuit guy went through his air supply like a Shop Vac but then even when he was not in his drysuit he went through his air like a Shop Vac. But, he was sure to let all know of his technical diving prowess.

Just like the rednecks 'roun'hea think big tires attract girls to their pu trucks, apparently some divers think the same way about a dry suit.

As to the size of the tires, I have noticed no difference in my attractiveness to the opposite sex despite the tire size reduction. But then, I have always been challenged in that department anyways, good thing I have a great personality. Maybe if I had a drysuit it would help me out there?

LOL.

When one uses every weight in the bucket to sink one's drysuit leaving none for anybody else, then that person is not popular.

N

Maybe, just maybe, the answer had already been given in one of the posts above.

Just saying.

---------- Post added December 24th, 2013 at 11:29 AM ----------

I dive a dry suit in warm water because I get COLD, and also because, if I'm going to do 4 dives in a day, I'd much rather slip into a dry suit four times, than struggle into a wet, chilly, uncooperative, thick wetsuit four times. I have done things both ways, and I know which I prefer. I do not see any difference between gas consumption in a wetsuit or in a dry suit, in the same water conditions. But I am very familiar with a dry suit, and I do not move fast when I dive. I will absolutely admit that there are drag differences -- they are quite noticeable when you are trying to keep a team together on scooters, just as the difference between doubles and a single tank is noticeable. But I have never in my life swum as fast as a scooter pulls me, nor do I intend to try.

Agreed.

Also, anyone who has ever dived in a wetsuit off a speed boat would know that the evaporative cooling that takes place after a dive when the boat is heading back to shore, will make most divers huddle down on the floor and their teeth chatter. Even in ambient air temps of 35 deg C and water temperatures of 30 dec C or more.