Weight difficulties and fin positioning

[rhelmy]

I am a newbie and I have been practicing proper weighting at every dive I have done so far. So far, I have fight to start descending. After 10 ft, I start descending easily. At the surface, I exhale all my breath and breath shallow while using my arms to push me down. At 10ft, I start to desend easier.

I am in fresh water, using a 2 piece 7mm wetsuit, with booties, no hood. My tank is an AL80 filled to 2800psi. At the surface with only 500psi on the tank, no air in the BC, I will float at eye level. I am using 26 lbs of lead. With no air in my lungs I will sink about a foot and stop. When I breath in I go to the surface. At this weight, When I get below 10 feet, I start to descend easily. When I get 30 ft, I feel like I am overweighted, as it takes several adjustments of air in the BC to become neutral.

If I go to 30 lbs, I descend from the surface easier, but after 10 feet, I start descending faster than I think I should. (I could be wrong, I am a newbie)

I understand that the wetsuit will compress, thereby making me less boyaunt (I am guy, cannot spell).

The other situation I have is my fins, When I descend my legs start to bend and my fins get behind me causing me to lose my balance. What is the best position for my fins to be aimed towards.

Question, If I stay at 26 lbs, Descending from the surface is a chore and with my arms flapping I don't think that looks professional, If I go to 30, I start easier, but I am not sure the rate of descend is normal.

Any advice is Appreciated, as I want to be a good dive buddy.

 

[wackodacko]

what about try 28 lbs?
i have pretty much the same setup and same problem as you (except I wear a hood and am in saltwater) last week, I used 30lbs and got down normally..it was great! this week i changed to a neoprene weightbelt and ankleweights and i was wearing 33 and still couldnt get down! !??!!? what.. well, so at the bottom, i added another 3 so all in all i had 36.. they say that some days you need a diff amt of weights cuz of what you ate last nite, and other external factors.. but they also say that the more experienced you are the less weight you need beacause you can handle ur lungs easier .. ?

 

[Uncle Pug]

Several issues here:
1) To get the correct weighting you need to use a tank with 500 psi. You should be neutral with no air in the BC at ~10' and rise or sink by breathing. In other words you must weight yourself correctly for the end of the dive not the beginning.

2) The extra weight that you will be carrying is equal to the weight of the air that is missing from a full tank... once you breath that air it will no longer be holding you down and if you didn't carry weight to make up for it you would pop to the surface near the end of the dive (not good.)

3) Properly weighted you will be able to descend easily at the beginning of the dive and you will in fact need to add air to the buoyancy compensator (BC) to adjust for the compression of your wetsuit and for the extra weight you are wearing for the end of the dive with an empty tank because at the beginning your tank is full.

4) As the dive progresses and you use your air you will find yourself getting a little buoyant... at this point you need to let a little air out of the BC to compensate and get back to neutral.

5) Repeat 4) in small amounts throughout the dive.

6) The correct fin position is out behind you... and the correct position for your body is horizontal as this provides maximum resistance to movement up and down in the water (slowing descents and ascents) and minimum resistance to movement forward in the water (easier swimming and better air consumption rate.) It also keeps your fins from digging up the bottom.

7) Typical rototiller divers are over weighted, semi- upright in the water, not using air in their BC to become neutral and finning like mad... stirring up the bottom... and at times even touching the bottom digging a trench as they go. Comments heard at the end of the dive usually include, "Great dive but the viz really sucked."

Do 1 thru 6 and you won't do 7

 

[Spectre]

wackodacko once bubbled...
but they also say that the more experienced you are the less weight you need beacause you can handle ur lungs easier .. ?

You're natural reaction in a stressful situation is to 'save' air in your lungs. You breathe rapidly and often at the top of your lungs and therefore float more [remember, you can displace about 9 lbs with your lung capacity!].

At the beginning of the dive it's tough, and at the end of the dive it's even tougher, 'cause now the weight from the air in your tanks is gone, and you're trying to fight that buoyancy as well...

As you get more experience you relax more, and you'll find you'll be able to shed more weight.

As far as your decent speed goes. Yes, your wetsuit'll compress and you'll start going faster. However, there is absolutely no reason you have to wait until you collide with the bottom to put air in your BC. Just be careful as you start to get used to that, since you don't want to put too much and start back up! Eventually you'll have complete control of your decent... keeping up with the suit squeeze with your BC so you're actually neutrally buoyant the whole way down and just using your lung control to continue your decent...

 

[WreckWriter]

Unconsciously I bet your feet are moving. Cross your ankles when you exhale, bet you sink like a rock.

Tom

 

[JimC]

The newer you are the more weight you need.

A few questions.

Is the suit new?
How deep has it been?
Are you totaly motionless when your decending?

Even tinny movments and "fighting it" will cause you to need many lbs extra weight. Depending on your size, you will probably drop much of that weight over your next 10 or so dives. While each person is diferent, in my 7mm, AL80 I use 18 lbs (5'11"/ 180lbs)


With a wet suit its normal to ad lots of air as you decent. The wet suit becomes a LOT less boyant as it compresses. This is very normal. Most of your lead is for getting you down to 20-30 feet.


Idealy your fins should be cocked in behind your but. You should be horizontal to the knees, then the knees bent up and your feet/fins horizontal and pointing back.

Get on your stomack on the floor. Lift your lower leg up so its sticking straight up, then bend your feet to point back. Then arch your back so your looking forward and your knees are just up off the floor... Uncomfortable ain't it? In the water its a much much more friendly position.

 

[Scubamedicjoe]

well couple things come to mind, you would could use the a Advanced Buoyancy class to asist you in this mattrer. second if this is new dive suit till it gets compressed a couple of times it will need more weight , and like somone said the best position is horizontal just food for the thought

 

[rhelmy]

My suit is new, and the maximum depth it has seen has been 30 feet for 20 minutes. I am 5'8" and 190 lbs (pudgy). I haven't been out on any tours thus far, as that I do not want to damage anything underwater. I have been practicing in a rock quarry now for five dives (plus the 4 check out dives). Based on what I read now, I should move to 30 lbs, practice, and then reduce to 28lbs after the suit gets a workin.

I also understand that it is ok to add air into the BC to slow down the rate of descend. Is this better than kicking with the fins to slow down. I figure with the fins kicking, that could cause the botton to kick up.

To date, I do not have any panic problems, and I am not nervous about being underwater.

I will be doing the advance water in September. I just wanted to become good at the existing skills taught in the open water before advancing.

 

[JimC]

I also understand that it is ok to add air into the BC to slow down the rate of descend. Is this better than kicking with the fins to slow down. I figure with the fins kicking, that could cause the botton to kick up.

Between your BC and your lungs idealy you should be able to decend at a comfortable pace stoping at a desiered depth. As you decend add air to your BC to offset boyancy loss in the suit. Use your lungs to fine tune. You should not kick/fin/hand paddle to controll your depth.


As for the new suit, once you have it down to 60-90 feet a few times it will loose a good bit of boyancy. I'm guessing you'll end up around 22lbs after a few dozen dives.