Help with some trim issues

digital_steve · November 13th, 2007, 04:42 AM

Hey all,
I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance.
This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can.
I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them.
I'm also using shotbag weight... not sure if that's an issue.

Any suggestions would be great

dsteding · November 13th, 2007, 05:03 AM

Honestly, get some of that weight off your back. A weight belt may be needed, it is certainly one of the standard recommendations for someone in your position.

digital_steve · November 13th, 2007, 05:26 AM

Doesn't a weightbelt sit weird or interfere with the backplate & harness?

dsteding · November 13th, 2007, 06:25 AM

Quote: (Originally Posted by digital_steve)

Doesn't a weightbelt sit weird or interfere with the backplate & harness?

Nope. I use one with singles and doubles diving dry, have up to 8 kg of weight on it at times depending on exposure protection.

People try and eliminate the weight belt sometimes, and sometimes it can be done. Other times, it is needed to move some of the weight down on the body and prevent heads-down trim.

If this is happening to you while in a single tank, a weight belt is the first obvious answer. The more subtle answer is that you'll get used to trimming out a variety of rigs by adjusting your body position.

digital_steve · November 13th, 2007, 06:34 AM

Cheers
I'll chuck on a weightbelt and throw some weight on it and leave about 6 pounds in my original pockets and see how i trim out

thanks

TobinGeorge · November 13th, 2007, 07:04 AM

Quote: (Originally Posted by digital_steve)

Hey all,
I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance.
This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can.
I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them.
I'm also using shotbag weight... not sure if that's an issue.

Any suggestions would be great

You are recieving some very good suggestions. Let me add the following;

Start with a careful weight check, you may be using more than you need.

In heavier exposure suits and modest sized single tanks my target is to be eyelevel at the surface with no gas in the wing and a full cylinder. (I rely on compression of my suit from the surface to ~15 ft to compensate for the gas consumed) This approach of course won't work in thin suits.

It's very possible that the wing you are using may not be easily fully vented. That leads to carrying more weight. Big weight belts can interfer with your plate and harness.

Working hard to solve a trim problem, and then discovering your total weighting is off will require repeating the trim exercize again.

Good luck,

Tobin

digital_steve · November 14th, 2007, 01:00 AM

Just out of personal interest...
Is using a weightbelt a more recommended weight solution that 'integrated' weight in DIR?
I see a lot of posts around the ol' internet about weighting rigs with no ditchable weight, i.e. p weight, tail weight etc.
I'm a bit confused as too which is the more 'standard' way... especially for singles

TobinGeorge · November 14th, 2007, 01:22 AM

Quote: (Originally Posted by digital_steve)

Just out of personal interest...
Is using a weightbelt a more recommended weight solution that 'integrated' weight in DIR?
I see a lot of posts around the ol' internet about weighting rigs with no ditchable weight, i.e. p weight, tail weight etc.
I'm a bit confused as too which is the more 'standard' way... especially for singles

Steve,

The concept you need to learn is the "balanced rig"

In short can you swim up your rig if you have a buoyancy failure? If not you need to be able to drop enough ballast to allow you to swim it up.

This becomes less of an issue with the use of drysuits, as the suit provides a redundant means of buoyancy.

Personally I use a combination of non ditchable ballast on my backplate, a slightly negative LP steel tank, and some weight in a belt if I'm diving single tanks in a heavy wetsuit.

This combination allows both allows me good horizontal trim, due to the placement of the weights, and the ability to drop about 8 lbs (lead + can light) should I ever need to. I can swim up the rest.

Tobin

*Brian Allen* · November 14th, 2007, 09:33 AM

You mentioned that you get air migration to your feet, which then exacerbates the problem. Here's a couple of points to think about:

How much air do you run in your drysuit? Can it migrate?

What fins do you use? Can you extend your legs to counterbalance until you sort the rest?

Where do you position your tank? Can you still reach the valve?

Where do you position your lead?

Can I get my head right back to touch the valve so I can see straight ahead when in trim?

What shape is your wing?

Is your rig secure, so it can't move and put you off balance?

Are you weighted correctly? ie can you hold a stop comfortably at 3m with nearly empty tanks, and completely empty wing and drysuit, without the use of any propulsion?

When approaching a new setup, I run through all the above in my head, and make small adjustments until I'm happy.

Brian

*JGrogan* · November 14th, 2007, 10:41 AM

Steve,
I think the positioning of the weights may be a bit of a red herring. What size cylinders are you using?
Short cylinders positioned low on your backplate will still be relatively high. You should try to get long cylinders as the weight is distributed over a larger area.
Another thing to consider is using a p-weight rather than a weight belt.
Finally, years ago when diving lighter cylinders, I used to strap weights to the lower part of my cylinders to get a better weight distribution - that often made a big difference.
Best,
John.

Quote: (Originally Posted by digital_steve)

Hey all,
I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance.
This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can.
I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them.
I'm also using shotbag weight... not sure if that's an issue.

Any suggestions would be great

November 13th, 2007, 04:42 AM	#1 (permalink)
digital_steve(Offline) New Member Join Date: Aug 2007 Location: Australia Posts: 130	Help with some trim issues Hey all, I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance. This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can. I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them. I'm also using shotbag weight... not sure if that's an issue. Any suggestions would be great

November 13th, 2007, 07:04 AM	#6 (permalink)
TobinGeorge(Offline) New Member Join Date: Nov 2005 Location: Southern California Posts: 568	Quote: (Originally Posted by digital_steve) Hey all, I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance. This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can. I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them. I'm also using shotbag weight... not sure if that's an issue. Any suggestions would be great You are recieving some very good suggestions. Let me add the following; Start with a careful weight check, you may be using more than you need. In heavier exposure suits and modest sized single tanks my target is to be eyelevel at the surface with no gas in the wing and a full cylinder. (I rely on compression of my suit from the surface to ~15 ft to compensate for the gas consumed) This approach of course won't work in thin suits. It's very possible that the wing you are using may not be easily fully vented. That leads to carrying more weight. Big weight belts can interfer with your plate and harness. Working hard to solve a trim problem, and then discovering your total weighting is off will require repeating the trim exercize again. Good luck, Tobin __________________ http://www.deepseasupply.com

November 14th, 2007, 01:22 AM	#8 (permalink)
TobinGeorge(Offline) New Member Join Date: Nov 2005 Location: Southern California Posts: 568	Quote: (Originally Posted by digital_steve) Just out of personal interest... Is using a weightbelt a more recommended weight solution that 'integrated' weight in DIR? I see a lot of posts around the ol' internet about weighting rigs with no ditchable weight, i.e. p weight, tail weight etc. I'm a bit confused as too which is the more 'standard' way... especially for singles Steve, The concept you need to learn is the "balanced rig" In short can you swim up your rig if you have a buoyancy failure? If not you need to be able to drop enough ballast to allow you to swim it up. This becomes less of an issue with the use of drysuits, as the suit provides a redundant means of buoyancy. Personally I use a combination of non ditchable ballast on my backplate, a slightly negative LP steel tank, and some weight in a belt if I'm diving single tanks in a heavy wetsuit. This combination allows both allows me good horizontal trim, due to the placement of the weights, and the ability to drop about 8 lbs (lead + can light) should I ever need to. I can swim up the rest. Tobin __________________ http://www.deepseasupply.com

November 14th, 2007, 09:33 AM	#9 (permalink)
Brian Allen(Offline) GUE Instructor Join Date: Nov 2005 Location: London & Plymouth Posts: 594	You mentioned that you get air migration to your feet, which then exacerbates the problem. Here's a couple of points to think about: How much air do you run in your drysuit? Can it migrate? What fins do you use? Can you extend your legs to counterbalance until you sort the rest? Where do you position your tank? Can you still reach the valve? Where do you position your lead? Can I get my head right back to touch the valve so I can see straight ahead when in trim? What shape is your wing? Is your rig secure, so it can't move and put you off balance? Are you weighted correctly? ie can you hold a stop comfortably at 3m with nearly empty tanks, and completely empty wing and drysuit, without the use of any propulsion? When approaching a new setup, I run through all the above in my head, and make small adjustments until I'm happy. Brian __________________ ...dive planning again ... GUE fundamentals and Halcyon Equipment Online www.ocean-explorers.co.uk

November 13th, 2007, 05:03 AM	#2 (permalink)
dsteding(Offline) 2,000th member Join Date: Mar 2007 Location: Seattle Posts: 80	Honestly, get some of that weight off your back. A weight belt may be needed, it is certainly one of the standard recommendations for someone in your position.

November 13th, 2007, 05:26 AM	#3 (permalink)
digital_steve(Offline) New Member Join Date: Aug 2007 Location: Australia Posts: 130	Doesn't a weightbelt sit weird or interfere with the backplate & harness?

November 13th, 2007, 06:25 AM	#4 (permalink)
dsteding(Offline) 2,000th member Join Date: Mar 2007 Location: Seattle Posts: 80	Quote: (Originally Posted by digital_steve) Doesn't a weightbelt sit weird or interfere with the backplate & harness? Nope. I use one with singles and doubles diving dry, have up to 8 kg of weight on it at times depending on exposure protection. People try and eliminate the weight belt sometimes, and sometimes it can be done. Other times, it is needed to move some of the weight down on the body and prevent heads-down trim. If this is happening to you while in a single tank, a weight belt is the first obvious answer. The more subtle answer is that you'll get used to trimming out a variety of rigs by adjusting your body position.

November 13th, 2007, 06:34 AM	#5 (permalink)
digital_steve(Offline) New Member Join Date: Aug 2007 Location: Australia Posts: 130	Cheers I'll chuck on a weightbelt and throw some weight on it and leave about 6 pounds in my original pockets and see how i trim out thanks

November 14th, 2007, 01:00 AM	#7 (permalink)
digital_steve(Offline) New Member Join Date: Aug 2007 Location: Australia Posts: 130	Just out of personal interest... Is using a weightbelt a more recommended weight solution that 'integrated' weight in DIR? I see a lot of posts around the ol' internet about weighting rigs with no ditchable weight, i.e. p weight, tail weight etc. I'm a bit confused as too which is the more 'standard' way... especially for singles

November 14th, 2007, 10:41 AM	#10 (permalink)
JGrogan(Offline) GUE Join Date: May 2006 Location: London Posts: 442	Steve, I think the positioning of the weights may be a bit of a red herring. What size cylinders are you using? Short cylinders positioned low on your backplate will still be relatively high. You should try to get long cylinders as the weight is distributed over a larger area. Another thing to consider is using a p-weight rather than a weight belt. Finally, years ago when diving lighter cylinders, I used to strap weights to the lower part of my cylinders to get a better weight distribution - that often made a big difference. Best, John. Quote: (Originally Posted by digital_steve) Hey all, I'm having some trim issues... I'm now recently getting into trouble with being way too heads down... which of course means air migration to the feet and just general annoyance. This seems to have occured as i've dropped some weight off. I'm currently diving a zeagle backplate and wing that has some pockets attached to the plate for weight (i hate weightbelts) so put all my weight there. I'm using a steel tank and setting it as low as i can. I'm thinking that maybe my harness is rigged too high... even though when diving the shoulder straps feel loose and i can move them (the rig doesn't move though) i'm assuming it's just set to high on my body. originally i thought that because the shoulders were a bit loose i was going to have to tighten them. I'm also using shotbag weight... not sure if that's an issue. Any suggestions would be great