Drysuit vs BCD bouyancy control

[JeffG]

Just wondering, did you get teased by engineers when you were at university?

Now thats funny in...oh so many ways

 

[Zero]

BCD (Bouyancy Control Device)

Drysuit (Environmental Protection/Climate Control)

Hmmmmm?

"Bright light glows overhead!"

Interesting synposis!

 

[TeddyDiver]

Anytime you add air into a closed space in your dive system it affects buoyancy. So adding just enough air to make the suit comfortable adds to positive buoyancy. Some people do this more so than others. Some people of course use only their drysuit.

It also depends a bit on what kind of suit you have and your weighting. A neoprene suit squeezes all the way down so I am adding air several times to reduce the squeeze for example. I am also adding air to my wing for primary buoyancy concerns. If I used my suit only I would have a large air bubble to manage in my suit, it burps out more easily, etc. At 50' it's not terribly significant. At 150' I would look like the Stay Puff Marshmallow man if using only my suit for buoyancy.
--Matt

Okay, that's about right. Adding air in DS to be comfy ads boyancy accordingly EXCEPT when you (and I) use neopren DS. While neoprene squeezes it's needed to compensate it's part in your BC like with WS. The amount of air needed in your DS depends the amount of underclothing, if none, or only t-shirt 'n boxers, theres no need to inflate DS. Infact then theres no need to DS when Semidry would do the thing.
Some of the people who prefer use of BC more than DS are either overweighted or have too large DS (sorry but thats the case). In the worst case both. Pattern: Too large DS and you can't squeeze the extra air out=>more weight needed for neutral boyancy!

 

[matt_unique]

Okay, that's about right. Adding air in DS to be comfy ads boyancy accordingly EXCEPT when you (and I) use neopren DS. While neoprene squeezes it's needed to compensate it's part in your BC like with WS. The amount of air needed in your DS depends the amount of underclothing, if none, or only t-shirt 'n boxers, theres no need to inflate DS. Infact then theres no need to DS when Semidry would do the thing.
Some of the people who prefer use of BC more than DS are either overweighted or have too large DS (sorry but thats the case). In the worst case both. Pattern: Too large DS and you can't squeeze the extra air out=>more weight needed for neutral boyancy!

You can't comfortably dive a neoprene drysuit without adding air below about 10' in my experience. You would experience extremely uncomfortable squeeze to the point of bruising. Once I made a fast descent and I had not connected my drysuit inflator hose. I stopped at 50' realizing my mistake, connected my hose, then continued. When I surfaced I had bruises on my shoulders and elsewhere. It's like a vacuum pack without adding air. Before I realized the cause I called DAN and spoke with a Doc. The Doc specifically asked me if I was diving dry sans inflator hose for a period of time because she had previously seen the same bruising I was describing.

--Matt

 

[Daryl Morse]

You can't comfortably dive a neoprene drysuit without adding air below about 10' in my experience. You would experience extremely uncomfortable squeeze to the point of bruising. Once I made a fast descent and I had not connected my drysuit inflator hose. I stopped at 50' realizing my mistake, connected my hose, then continued. When I surfaced I had bruises on my shoulders and elsewhere. It's like a vacuum pack without adding air. Before I realized the cause I called DAN and spoke with a Doc. The Doc specifically asked me if I was diving dry sans inflator hose for a period of time because she had previously seen the same bruising I was describing.

I've seen something similar with a shell suit. A guy I dove with didn't inflate his suit enough and he was covered with "crease marks". I think the effect is like an extended hickey along the lines where the suit bunched up. Not sure how long it took them to go away but I'd guess on at least a few days. (Thankfully, I forgot how long it takes hickeys to go away many years ago.)

 

[SubMariner]

I've seen something similar with a shell suit. A guy I dove with didn't inflate his suit enough and he was covered with "crease marks". I think the effect is like an extended hickey along the lines where the suit bunched up. Not sure how long it took them to go away but I'd guess on at least a few days. (Thankfully, I forgot how long it takes hickeys to go away many years ago.)

Yup... the infamous "suit hickey". One way to help stave them off (besides the obvious one of having enough air in your suit to prevent the squeeze) is to always make sure you wear something that totally covers your legs AND your arms. This can even be a long sleeved t-shirt and a pair of bike leggings.

 

[Daryl Morse]

Every computer scientist did. We were the ones who weenied on the math courses and took the easy route to high paying careers. Most engineers secretly envy computer scientists because they know in their hearts that computer scientists, while not smarter, are definitely more task oriented and pragmatic, something every engineer wishes he had.....However, due to a genetic social deviation (for lack of a better term) engineers are unable to express envy and it comes out as incessant teasing.

LOL! That brings back memories. At UBC where I graduated from, the comp sci students hated the ee and comp eng students because the latter always got the top marks in the comp sci courses. The ee and comp eng students hated the comp sci students because they got priority in the comp sci courses on registration day. At UBC, the engineers didn't tease, they tanked their victims (threw them into a fountain). Also, there was a long standing rivalry between forestry students and engineers. The forestry students used to vandalize the engineering cairn (big huge painted concrete E) by burning it, hammering it, and even with explosives. One year, they leveled it. The engineers tanked them back. Ah, the place of higher learning.

I guess this doesn't have much to do with diving...

 

[Diver0001]

LOL! That brings back memories. At UBC where I graduated from, the comp sci students hated the ee and comp eng students because the latter always got the top marks in the comp sci courses. The ee and comp eng students hated the comp sci students because they got priority in the comp sci courses on registration day. At UBC, the engineers didn't tease, they tanked their victims (threw them into a fountain). Also, there was a long standing rivalry between forestry students and engineers. The forestry students used to vandalize the engineering cairn (big huge painted concrete E) by burning it, hammering it, and even with explosives. One year, they leveled it. The engineers tanked them back. Ah, the place of higher learning.

I guess this doesn't have much to do with diving...

Well, I did learn to scuba dive at university.....

At SFU the Engineering students did tend to perform better academically than the cs students, especially in the math courses, but they also had these "Engineering" courses worth 10 credits (that's more than 3 times a normal course) where all of the students passed with perfect marks. I have no idea what the content was but from the outside it looked like the engineering department was engaged in GPA padding. I asked the head of the CS department once why "we" didn't have courses like that and she just said "becasue CS students don't need them".... You can take that to mean several things but to me it looked like the rivalry didn't end at the undergrad level.

R..

 

[TeddyDiver]

You can't comfortably dive a neoprene drysuit without adding air below about 10' in my experience. You would experience extremely uncomfortable squeeze to the point of bruising. Once I made a fast descent and I had not connected my drysuit inflator hose. I stopped at 50' realizing my mistake, connected my hose, then continued. When I surfaced I had bruises on my shoulders and elsewhere. It's like a vacuum pack without adding air--Matt

That's what I meant to say, sorry being inaccurate. With neoprene DS air is needeed both in the DS and in the BC. In the DS becouse of the air in the underwear, and in the BC becouse of the air in the neoprene.

 

[Lightning Fish]

...Also, there was a long standing rivalry between forestry students and engineers. The forestry students used to vandalize the engineering cairn (big huge painted concrete E) by burning it, hammering it, and even with explosives. One year, they leveled it. The engineers tanked them back. Ah, the place of higher learning.

I guess this doesn't have much to do with diving...

There was a rivalry between the engineers and anyone within arms reach.

I thought it was the agricultural students who levelled the cairn. Around 1989/90 wasn't it? There were rumours of lawsuits and criminal charges over that event.

Bill.