Another weighting question for the more experienced divers

[LowDrag]

So...can anyone tell me how it is possible to do a dive with 24 lbs get out of the water go have lunch and an SI of 1 hour get back in the water with the same weight/gear and not be able to sink???


My wife and I dove Cove 2 in Seattle yesterday and had this happen to both of us. We wore exactly the same gear after lunch as from before lunch and could not sink. The only difference was that I carried her gear to the water for her on the first dive and she carried her gear to the water on the second dive. We had fish and chips at the Marination Station right there on the pier then walked around and talked to some other divers and then got into our gear for our second dive. My wife was wearing 24 lbs and I had 26 lbs IIRC which worked great for the first dive but both of us had to add extra weight for the second dive.


Any ideas? We are both very curious about what was up rather than down...hehehe


Thanks,
LowDrag

 

[chrpai]

You might have sources of buoyancy such as air trapped in your wetsuit or hood or trapped in the BCD. You think you have it emptied out but in fact, you don't.

Learn to relax at the surface, let the water really seep in (and then stay ) and lean in different directions and really get the air out of the BC. A back inflate / wing really helps because it's easier to get the air out.

You also might have been tense, holding extra air in your lungs or finning without realizing it. This happens on a night dive sometimes too.

 

[redacted]

Assuming you did not change tanks from steel to Al, did you have to sleep in separate rooms that night?

A pound or two might just have been a comfort level thing. Sounds like you may have been just right on the 1st dive. Once you get there, sometimes you just have to work a bit harder expelling trapped gas and giving it the big exhale at the surface in order to descend.

 

[LowDrag]

We are diving this equipment:

Her:

3000 PSI AL80 tank
White's Fit dry suit
White's Rock boots
White's zippered hood
Aqualung Lotus i3 back inflate BC
Oceanic 3mm gloves
ScubaPro Mini Spectra mask
ScubaPro Twin Jet split fins
XS Scuba nylon weight belt with weights listed above
One Princeton Tech pistol grip light
Under armor type wicking layer (Paradox brand)
EMT shears stowed in a pocket

Me:

3000 PSI AL80 tank
White's Fusion Bullet
White's Rock boots
White's Hood - no zipper
Hollis S38 wing with SS backplate
Oceanic 3mm gloves
Hollis M4 mask
Hollis F1 fins
DUI weight harness with weights listed above
One DRIS 1000 Lumen light on a spring coil bungee
Under Armor wicking layer - Cold weather thickness
One dive knife - forget the brand but it is about 10" in length
EMT shears on my harness

I also carry a very small water proof bow in my right pocket for my car/truck key. It is the size of a pack of cigarettes. Oh and a slate in my other pocket.

Nothing changed from dive to dive. As for the trapped air, I would have to question that one. She was in the water for quite a bit moving this way and that trying to squish all the air she could find so I am not sure if that would be a concern. I looked under the surface and I did not see any ballooning of her suit below her weight belt and above water she did not look inflated either.

 

[chrpai]

Well, you didn't provide all that information in the first post. I wasn't there so I can only tell you of possible sources of buoyancy / lift.

 

[ianr33]

This is perplexing.

I could understand it if you had a very light lunch, but not something heavy such as fish and chips.

 

[LowDrag]

Assuming you did not change tanks from steel to Al, did you have to sleep in separate rooms that night?

A pound or two might just have been a comfort level thing. Sounds like you may have been just right on the 1st dive. Once you get there, sometimes you just have to work a bit harder expelling trapped gas and giving it the big exhale at the surface in order to descend.

Nope...no tank change either.

LOL!!! Nope same room...

Comfort is good. She is using her new Lotus and LOVES it. After the first dive she came up glowing over how well her new BC worked for her. I was really amazed at how well she took to it right off.

I get the big exhale thing but she tried that too. This is where we are trying to figure out what was happening. We did everything the same but still had to struggle to get down. She even tried swimming down and that was a struggle in itself.

Well, you didn't provide all that information in the first post. I wasn't there so I can only tell you of possible sources of buoyancy / lift.

You're right and I should have. Sorry about that, I should have posted after my second cup of coffee...


I added the tank type to the second post as well.

This is perplexing.

I could understand it if you had a very light lunch, but not something heavy such as fish and chips.

I know right? No "floaty lunch" for us...hehehe

 

[Searcaigh]

Gas ........ ?

 

[LowDrag]

Gas ........ ?

21%. Oh...you mean CH₄? Nope...No beans there.

 

[chrpai]

Did you ever say how much extra weight? Did you do a neutral buoyancy check at the end of the dive?