Floaty feet - bcd type?

Ive been diving for many years with no trim or buoyancy issues. Recently i invested in a new bcd new new psotively buoyant fins. Things started to change. Ive now started cooler water diving and im face planting whilst underwater leading to an uncomfortable dive and a very sore back.m heres some info:
- female and short
- using a aqualong pearl bcd
- changed to negatively buoyant fins (this helped a little)
- 7mm wetsuit
- changed from 5mm to 3mm ankle booties (helped a little)
- moved all weights to weight belt and integrated pocket (not in trim pockets)also helped a little.
- tank sitting as low as possible in the bcd
- using steel tanks, 10L. Tried 12 but they are way too long for me.
- hate ankle weights, have strong currents i need to kick with ease.

Tropical diving, 5mm suit, al tanks im fine until the end of the dive when air gets lower. NEVER had this issue using rental bcd's. Even after all. The changes as above its just unbearable.

I had rhought it was the fins, im now thinking it might be the bcd and how it ends up positioning the tank.


Question: would a rear inflation bcd, help or make the trim worse? Im struggling to think of the physics involved here, and which way it will tip me if at all.


thanks so much!

Fins are the furthest pivoting part of you. Head up, fins pushed back, as in straight legged and don't move. If you fall flat on your face you need heavier fins or ankle weights, plane and simple. I would vote for a heavier fin.

Thanks Peter. That was my thoughts too, so moved from the sewing nova to the mares quattro's. After trying to be a plan, yes i still fell flat on my face, although definitely more gently than with the nova's. So.... jet fins? I'm so small i don't know if i'd cope!

When you put air in your BC, where does the air go, is it free to go to the part of the air cell nearest your neck? How does adding air effect your trim?

The physics are like a playground see-saw.

I hate to suggest ankle weights for diving wet *so I won't) but as a short female you share a situation a few gals in my life are dealing with.

Often divers like yourself run out of body length and the weight belt is up in the BC and and it doesn't help much to move weights. If you can try something like a DUI weight harness you can drop that weight a little below your natural waist/hips without risk of losing a weight belt. That can influence the see saw in a big way! Your rig may layer together nicer too.

Put the 5mm booties back before you get cold feet, it's not worth the sacrifice!

Pete

MA:

Thanks Peter. That was my thoughts too, so moved from the sewing nova to the mares quattro's. After trying to be a plan, yes i still fell flat on my face, although definitely more gently than with the nova's. So.... jet fins? I'm so small i don't know if i'd cope!

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The small/medium jet fins are easier to use then the quattros cus they feel softer and are shorter. Quattros are not really negatively buoyant slightly perhaps but not enough to trim you out based upon what you have described.

You can also strap a couple of weights at the very bottom of the tank which might be a bit unstable initially but won't be that difficult to dive with.

If you really can't solve your problem... get a new bcd or diy a custom weight harness with pockets for your thighs.

Good luck.

What size foot do you have in mm?

My gal uses large Jets in the tropics over her 7mm booties. She also has a pair of XL Jets for cold water, which is the fin I use for both cold and warm water diving. Being foot heavy is easier to correct since you can just pull your feet up and in. If you want a paddle fin there are other brands like the Hollis F1 and others that are a hair lighter than Jets. Either way once you figure out what fin works throw some spring straps onto your fins.

Hi All,

Thanks for the feedback. I have a few things i can try next weekend. I'm also testing a couple of different bcd's to see if that will help.

Peter - my foot length toe to heel is 220mm - probably one of the causes of my issue!

I've actually always wanted jet fins, but had figured i wouldn't have the strength for them. I will try give them a shot after hearing they are easier than Quattro's. Thats if they come in size's small enough.

The DUI harness sounds interesting, also i might be able to shift more weight onto my existing belt and move it down a smidgeon.

Something has to work - I'm not giving up on cold water diving yet!

Try to arch your back and move your arms out in front of you. An arched back will make the air going towards the shoulders and arm moved forward will create more lift on a longer lever.

The shape of the air bladder CAN make a difference in how you tend to float. I've never dived a Pearl, so I don't know how they are made, but if they are wide and thick at the base of the bladder, it may be easy to get all the air you use parked there. When you add a lot of floaty neoprene on your legs, and no weight to counteract it, you have a recipe for being feet-up. We have this problem a lot with our OW students, who are in 7 mils of neo plus thick booties, and we just give up and put ankle weights on them. My former #1 dive buddy, who is one of the most beautiful divers you've ever seen, dove feet-up in his wetsuit. It wasn't until he switched to a dry suit (everything else stayed the same) that he was able to maintain flat trim without sculling.