2 Questions, 1 Forum

[ericg753]

Hi everyone,

Been 6 months since my last dive, I'm dying to get back into it again. That's a huge turnaround from my initial posts, not diving ever before and being overly nervous (normal when first starting out). I had construction done on the house so I'm paying the loan down, then will start scheduling my dives again. So to the questions:

1. I'm 1 dive away from getting my advanced certification, need to do the navigation dive. Other than using my compass, what exactly is entailed in a navi dive? I'm doing it in 2 weeks and have nowhere to practice other than my shops' indoor pool. I'd like to get a general idea of what's involved, the sooner the better.

2. I went to the Cayman Islands in April and did several adventure dives, including my first ever deep dives. The first day I did a deep dive, we went down to 107 feet. I remember when we were at our lowest point, I was able to breathe, but it was a bit labored and felt my entire rib cage "hurting" (almost like a strong bear hug). I imagine it was due to the pressure and I wasn't used to it. That, plus I had 2 cups of coffee that morning, a cigar the night before and a big dinner. I'm guessing all that had to do with it? I got nervous because I felt like I was starting to get into danger, so I signaled my buddy that I was having a tough time. The guide then started taking us up gradually and the feeling went away, though not 100%. I felt some after-pain in my ribs while on the boat after the dive, it lasted for a few hours then gradually went away.

So the question is, was I doing something wrong (other than the big meal and the 2 cups of coffee)? Or was it just that my body wasn't used to it (I did another deep dive the next day, this time only 95 feet - didn't bother me or at least I didn't notice it). The deep dive and going through the caverns was fun - actually I'll take the caverns in shallower water. The deep dives, although adventerous, got me a little nervous. I'll do it again, but it's not my first choice (my absolute favorites were the shore dives, wreck dives and a night dive!).

FYI I live on Long Island, NY. If anyone knows of any groups I can join for local dives next spring/summer, please let me know.

 

[Dive Right In Scuba 2]

Quick question on the deep dive.....were you wearing a jacket styled BCD and had to add a large amount of air to maintain neutral buoyancy?

 

[ericg753]

Aha....well, actually I wasn't wearing a suit for any of the dives because the water was so warm even at the deep dive. But yes I did wear a jacket style BCD with 22 lbs added. And yes I was neutrally buoyant (except of course when I was running low on air towards the end of the dives)

 

[drrich2]

The first day I did a deep dive, we went down to 107 feet. I remember when we were at our lowest point, I was able to breathe, but it was a bit labored and felt my entire rib cage "hurting" (almost like a strong bear hug). I imagine it was due to the pressure and I wasn't used to it.

It was not due to the pressure and should not have happened. I've been to around 132 feet or so, and did not feel any pressure on me. Within recreational limits, you should not feel pressure mashing/crushing your body. Yes, it compresses the air in your lungs and middle ears, the air you're breathing is denser and thicker, and of course it's forcing more nitrogen into your blood, hence the shorter NDL limits, but you ought not to feel like you're in a bear hug from water pressure.

I think what Dive Right In Scuba 2 is getting at is, did you perhaps have a highly inflated (and perhaps fairly tight?) BCD squeezing you?

Richard.

 

[Roman_66]

Aha....well, actually I wasn't wearing a suit for any of the dives because the water was so warm even at the deep dive. But yes I did wear a jacket style BCD with 22 lbs added. And yes I was neutrally buoyant (except of course when I was running low on air towards the end of the dives)

I think he mean that probably you didn't do proper weight check and 22 lb was too much, as result jacket BCD had large amount of air to make your neutral buoyancy and you had difficulty to breath.
Why you think that at the end of dive you can/should lose your neutral buoyancy ?
All idea of weight check and correct equipment is to be able to keep neutral buoyancy during all dive.

 

[Scubagolf]

22 lbs could be correct, or not. If you felt a "bear hug" at 107' I doubt it could be anything but your BC constricting due to putting air in it. Perhaps your jacket style BC was too tight to begin with. You likely went to max depth early in the dive, you had to add air to maintain buoyancy at depth, and then at the end if the dive you are probably down to <800 psi causing the difficulty in maintaining the safety stop. The fact that your chest and ribs actually hurt for hours post-dive is pretty strange. You might consider a back-inflate BC.

 

[Dive Right In Scuba 2]

Thanks for helping me make my point guys! I was hoping to get a reply before hitting the hay last night.

 

[Phantom Menace]

As the others have said it is most likely to have been your jacket BCD putting pressure on your chest. I have been to 130 ft free-diving and the sense of pressure then (when all your air cavities are genuinely compressed) is quite different to a 130 ft SCUBA dive when the air you breath matches the ambient pressure.

 

[CT Sean]

For Question #1, nav dive requirements, it likely varies by agency, but for our PADI AOW, we did a measured swim (100 feet I believe) counting fin kicks out and back. Pretty sure our instructor quizzed us on bearings (like if your heading is 90* and you take a right, what's your new heading). And we navigated a square (swim out X fin kicks, turn 90 degrees, repeat 3 more times to return to starting point)

Can't comment much about question #2, but 22 lbs with no wetsuit is a lot of weight. 22 may very well be right for you but it's way too much for most people. There's a good chance you had way more air in your BC than you realized and a jacket BC definitely "crushes" when filled too much

 

[ericg753]

Not sure what difference, or may be a huge difference, is that I'm a big guy. Former bodybuilder/gained gut over the marriage years. One instructor told me, when I was taking my shore dives for basic cert (PADI), is that the more bodyfat a person has, the more weighted they have to be. Hence probably why the 22 lbs.

I was wearing my newly purchased Scubapro Knighthawk BCD, I put it on in the store and fit perfectly. I don't THINK it was too snug but at 107 feet that velcro around my waist may have been snugger than I thought?

Very possible I had too much air in my BCD. I did test for neutral buoyancy at the surface, so at that point I was fine. Could be I was playing too much with my inflate/deflate. Also I'm still a newbie, was using my hands too much. Not sure if all of that played a factor.

FYI in case I didn't explain my situation correctly earlier, it wasn't that I couldn't breathe, it was a feeling of labored breathing and that in turn hurt my ribs/lungs/whatever I felt. Could be like NRich explained, the air is denser and thicker. Maybe because I'm still new at this (was totally new at deep dives, yes pretty much went straight down to 107 feet (slowly of course))....remember too that the next day I did another deep dive, this time only 95 feet and it didn't bother me (or at least I didn't notice anything).

Could be a combination of factors the first day is what it sounds like to me. Need more experience and correct BCD inflation/establish neutral buoyancy/proper weighting.


CT Sean, thank you for the explanation of the requirements for the navi dive.

Thank you everyone for your advice! Learning more and more about diving every day....