Trim Issues?!!? HELP!!!!!

[BB1]

Henrik:

Fins are Hollis F1 batfins, I've thought about jets but not sure they're much heavier.
Tanks are Faber 12.2L steels.
Tail weights seem to be the best recommendation so far.
I'll have a think over the tank hole/plate position suggestion as well, thanks

Kern:

Spot on with tank sizes. Suit buoyancy is fairly high - 26lb in a salt water pool at home test - Fusion tech LE with Arctic thermals.

Others in our training group could all manage the bubble with the same tanks but I'm keen to try predominantly using the wing for buoyancy.

The majority of our dives were short'ish duration shallow training dives - Gouldens sinkhole more times than I care to remember - so could keep track of gas consumption easily. On all the deeper/longer dives I was correctly weighted from the start.

Down & dirty was needed to keep on program with the training and this is why I'm now trying to fix the problem properly for the future with the benefit of time to try new things. Tail weight seems to be the recurring theme so will make one ready for next time out.

Grommet hole used was the middle one on a DSS 49lb wing. Only had to use the wing for buoyancy when carrying a deco bottle.

 

[TSandM]

Well, all the suggestions have been good ones. I just want to add my own experience. When I transitioned to doubles, my first set was very badly balanced for my body. I fought those tanks and fought those tanks . . . and one day, I borrowed a different set from a friend, and it was like coming home. I later worked with Bob Sherwood, who has a reputation for being able to help people trim out just about anything, and his conclusion? "I guess you CAN'T trim those tanks out!"

But even after I switched to the ones that fit me better, I still had head-heavy problems. I switched to an aluminum backplate, put more weight on my belt, and even sometimes dove with weights in my dry suit pockets.

Today, without changing any gear, I can balance those tanks out with a steel backplate. I learned how to do it with my body -- doubles are FAR more demanding of proper body posture underwater. Head up, knees up, back straight . . . You can trim out a lot more unbalanced load than it seems possible, when you begin.

I have to take my hat off to you, being brave enough to take a class in unfamiliar gear. These classes are hard enough, without struggling with gear issues at the same time.

Oh, and BTW, I have learned that, because caves go up and down and I have to do the same, it works best to keep the absolute minimum amount of gas in my suit that I can tolerate and stay warm and adequately mobile. Otherwise, I'm sure to encounter a slot that requires me to go head down, and is followed by a whole length of cave that doesn't permit me to drop my feet to get the gas out of them. It's just how it goes.

 

[BB1]

Apologies for big delay replying - pressures of work etc............

I really do thank my lucky stars for talking to Tobin at DSS when ordering a doubles wing setup - he said don't select another stainless plate as you already have one, get the Kydex and increase the tools in your armoury. I LOVE that kydex plate!

I'm going to try shifting all the weight to a belt for a first step and see how it goes.
Gaitors are a definite as well - should help keep air out the legs.
And then a progression to air in wing instead of suit though I would have found it very hard to complete some of the skills like being reel man reeling out while blind and buddy breathing - having to vent a wing as well would have been hard, venting a suit was easy - drop right shoulder and lift left slightly and carry on.

As you've all said - more practice. practice, practice as well with the combo to get it really nailed. Trim was OK (could always be a little better) until heading head first down slope, then trouble was but a moment away if I lapsed attention.

TSandM I'm not brave - just willing to take on a challenge and believe in myself. I read your blog of your early days and how far you've come since then and they are an inspiration along with many other SB'ers. Starting the course having never dived a drysuit and only a couple of pool sessions in twins was a challenge (the twins easier than the drysuit by far) but as our instructor said "If you are perfect at everything and don't make any mistakes then how can I teach you anything?". First time in real caves with overhead is a big eye opener (I think mine were like saucers!) but more practice will help - shame the caves are almost 2000 miles drive away.

I think I might have to write up a trip report for the cave forum as well to share our groups experience.

Thanks everyone for the advice and support!

Well, all the suggestions have been good ones. I just want to add my own experience. When I transitioned to doubles, my first set was very badly balanced for my body. I fought those tanks and fought those tanks . . . and one day, I borrowed a different set from a friend, and it was like coming home. I later worked with Bob Sherwood, who has a reputation for being able to help people trim out just about anything, and his conclusion? "I guess you CAN'T trim those tanks out!"

But even after I switched to the ones that fit me better, I still had head-heavy problems. I switched to an aluminum backplate, put more weight on my belt, and even sometimes dove with weights in my dry suit pockets.

Today, without changing any gear, I can balance those tanks out with a steel backplate. I learned how to do it with my body -- doubles are FAR more demanding of proper body posture underwater. Head up, knees up, back straight . . . You can trim out a lot more unbalanced load than it seems possible, when you begin.

I have to take my hat off to you, being brave enough to take a class in unfamiliar gear. These classes are hard enough, without struggling with gear issues at the same time.

Oh, and BTW, I have learned that, because caves go up and down and I have to do the same, it works best to keep the absolute minimum amount of gas in my suit that I can tolerate and stay warm and adequately mobile. Otherwise, I'm sure to encounter a slot that requires me to go head down, and is followed by a whole length of cave that doesn't permit me to drop my feet to get the gas out of them. It's just how it goes.

 

[Kern]

These are just some things I thought I'd add for your consideration.

As a comparison, on deep deco wreck penetrations, I use; A Fusion DS, vest & Mk 2 undies, steel 12x232 twin tanks, DSS steel plate, DSS 57 or OMS LG 45 wings, 9lb weight belt, no gaiters. I have no trim problems.

I use the DS for warmth, wing for buoyancy control. When I go into a passage that requires me to be head down, I don't have a large bubble in my DS that will move into my lower legs & feet, thus tipping me even further head down. Instead, I have a similar amount of gas required for buoyancy in my wing. The bubble therefore can't move past my waist, so the destabilising forces that I would have with a large bubble at the end of a long fulcrum don't exist. As you're longer than me this can only be exacerbated using the DS for buoyancy.

Correct posture also plays a part in good trim, especially if you need to move from horizontal to head down which is common on penetration dives. I know it may sound trite, but lack of experience really can play into these sort of problems. At the risk of being even more trite, going too far, too quick, can often lead to inculcating bad habits.

Of course there's only one way to deal with the experience problems. Get out there in your DS & doubles set up & dive, dive, dive. Whether you try varying methodologies or stick to what you're doing now is up to you. The main thing is to enjoy the dive, dive, diving while you gain more experience.