Diving doubles.... a trim issue

[ozJohnno]

Howdi,
I recently have gotten into diving doubles and I seem to be having some problems with trim, ie my legs go up and my head goes down.

In order to fix the problem, I bought online a set of APEKS RK3 fins. These are much heavier than my current set of fins and come in atn1.27kg each.

will this fix my trim problem? and what about the extra weight? Will I have to take the 2.5kg off my weight belt?

Cheers


Johnno

 

[Ministryofgiraffes]

You can also try ankleweights. Buddy of mine swears by them.

 

[Caveeagle]

Steel,or,aluminum?

Wet or dry?

Do you have the top bad all the way up to the top of the tanks, right where it starts to round off?

 

[JohnnyC]

Too many unanswered variables in the original post. Like @Caveeagle said, tank size and material? Exposure protection? Band height? How much other weight? Where is the weight distributed?

Sometimes swapping a pair of fins does it, but the RK3's are hardly negative. Aside from being floppy and generally poor performers, if you want a good set of negative fins, you want Scubapro Jet's or Hollis F1's.

 

[ozJohnno]

My setup is as follows

5mm semi-dry one piece
nth degree thermal top
I carry 4kg weight in a weight harness (the belts kept on falling off me)
halcyon steel plate
halcyon 60-pound wing.

I dive 12.2litre steel tanks
I put the tanks in the upper position on the backplate to facilitate me reaching the valves
There is a lower position that is approx 1.5 inches lower than the upper position. Maybe I will try to mount the tanks in the lower position

 

[KenGordon]

There are two types of RK3, the HD version is a heavier fin. I bought the ordinary RK3 particularly because they are light, but for a twinset I have F1s.

Whatever fins you use they are not made of lead, they displace quite a lot of water and so you cannon simply reduce your lead by their weight in air. The answer is always to do a proper weight check, calculations are just first pass guesses.

Going back to your trim issue. You can get tail weights which attach to the bottom bolt of the twinset and put some weight closer to your feet. Tail Weight Highland make one as a bag of shot.

Keep your head up and explore how the position of your arms makes a difference, also how bent your knees are.

Avoid ankle weights. They are very uncool, an entanglement hazard and can be very annoying to wear. They are popular with drysuit divers in the U.K. who are insecure about gas moving to their feet.

 

[W W Meixner]

Howdi,
I recently have gotten into diving doubles and I seem to be having some problems with trim, ie my legs go up and my head goes down.

In order to fix the problem, I bought online a set of APEKS RK3 fins. These are much heavier than my current set of fins and come in atn1.27kg each.

will this fix my trim problem? and what about the extra weight? Will I have to take the 2.5kg off my weight belt?

Cheers


Johnno

...

John...

You're too negative...

Get rid of all your ballast...with the S/S BP...and the steel tanks you should not need any additional ballast...especially diving with only a 5mm suit...

I dove ''tec configured'' recreational doubles for years...double HP steel 100's...and double HP steel 80's...with a dry-suit...I weigh approx 185 LBS...S/S BP...60 LB lift OMS ocean wing...and 95 LB lift OMS double bladder ocean wing when I dove with the kit in North Carolina with full 3mm wet suit...

No lead ever...I went for years without ever owning any ballast...

Even now with the rebreather...which is feather-weight...with dry-suit...18 LB. ballast...shot packs...

As far as fins...I've always sworn by OMS Slipstream...made from Monoprene...lots of power without the weight of pure rubber...

You need some practice time in a good pool or in the shallows in open water...preferrably accompanied by a proficent diver...

As has already been mentioned...avoid ankle weights...also when you move up to a dry-suit...buy a suit that fits properly...and avoid gaiters...don't become dependant on training wheels...

Best...

Warren

 

[johnkendall]

My setup is as follows

5mm semi-dry one piece
nth degree thermal top
I carry 4kg weight in a weight harness (the belts kept on falling off me)
halcyon steel plate
halcyon 60-pound wing.

I dive 12.2litre steel tanks
I put the tanks in the upper position on the backplate to facilitate me reaching the valves
There is a lower position that is approx 1.5 inches lower than the upper position. Maybe I will try to mount the tanks in the lower position

If there are 2 positions on the plate then it's not a halcyon. Also a 60lb wing is too big for Double 12s, you need the 40lb.
Do a proper weight check, with 40bar in the tanks and get rid of any excess weight.
Most trim issues are body position rather than equipment though. Stretch your legs out behind you more maybe.
See if you can get someone to take some video of you in the water (from the side).

 

[eelnoraa]

I think head heavy with steel double is not uncommon. Unfortunately, this is not likely to be fixed by adjusting postures or skill, you will need to make some changes with the equipment in your case.

I would say first try to switch to a AL plate. Instead of putting weight on a weight harness, get some tail weight mounted to the very low end of the double. Also switch to heavy fins like Jet of Hollis F1. With negative fins, only stretch your legs will help. The goal is to shift weight lower. But don't do ankle weight please.

As for wing, while I do agree 40lb will make your life much easier, 60lb isn't the cause of your heavy heavy problem. I will not make this switch just yet

 

[Marie13]

Make a tail weight with lead weight, webbing, and waxed cotton thread. Burn a hole at the top for it to go on bottom bolt.