Preparation for Cavern and Intro

[john844]

A buddy and I are wanting to take cavern and intro. We are both comfortable with the gear we currently use, but I am pretty sure it will have to change for cave usage.

The primary item of concern is the dreaded oms bungied wing. We are both using that wing style when diving doubles and need to change over to something else. The problem we ran into was trimming out any other wing. With the oms, everything happens nicely even when head down. Each of the other wings we tried had unsavory results and massive trim swings if I approached horizontal. Is this a training issue we solved with equipment?

We want to have the trim issues corrected and be proficient with any equipment changes before starting further training. As part of our adjustments with alternate wings, we moved the tanks down as low as possible and moved the wings as high as possible. I was diving dry, SS backplate, no additional weight, xsscuba lp 108's

I would hate to end up spending days of cave training classes on something I can fix at home. Should we bother trying to deal with this issue before class, or let the instructor correct it then?

Are there any other suggestions on modifications that we missed to help with this trim issue?

Thanks,
John

[Slüdge]

If the wing works for you, use it. If the instructor says you can't, find another instructor.

[gschaut]

Hi John- I'm only apprentice, going for full cave in April. So I'm sure there are many more qualified people here who can weigh in on this problem.

But for what it's worth, I also had some "trim" issues when I started. My thoughts are that trim should be dealt with as much as possible before starting cave classes. Any time you spend in a pool with equipment will be time well spent. Your instructor for cavern probably will expect you to have your trim and equipment issues dealt with before starting class. Cave class is about learning new skills, not fighting with equipment issues.

One solution I did exercise, was to schedule a day of private instruction time with my instructor BEFORE the official cave class. We were able to fine tune some trim issues that I was not able to deal with back at home (for me, it was converting to side mount).

As far as trim swings on backplate/wings, have you tried the Dive Rite Nomad (either JT or XT) in a pool? That ended up being my solution of choice. The Nomad wing has a bungee cord system that is hidden underneath the wing, and does not present a fouling hazard.

Good luck, and hope to be able to dive with you some day.

[john844]

Just to clarify, I don't have trim issues diving with my singles rig, or when diving the oms wing and doubles. The trim issues are there with other wings.

I did not have a nomad available to try. I think we tried an Oxycheq vertex?, DR Classic, and one other that I can't recall right now.

I have been lurking and reading this forum for almost 2 years. We just returned from a trip to FL to do some spring diving and practice task loading sessions. I am looking forward to being able to dive with some of the members here.

[JamesK]

If the OMS wing works, use it!

With the other setups were you going head down? Could it be that you have to much air in the feet of your suit? The trim problem is something you can always work out later, but I would do your Cavern/Intro in what you are currently comfortable in.

[john844]

Air in the feet of my suit is a possibility. I was not wearing gators. That does not seem to be an issue when diving single tank, but it could be a contributing factor.

On the other setups getting close to horizontal resulted in a rapid progressive loss of stability.

Maybe I read too many bungied wings of death posts. It sounds like taking my class is possible in this wing. This will be one of the first questions asked of my potential instructors.

[JamesK]

While I am not a huge fan of bungee wings, that is a personal thing. I just don't find them to be necassary, basically a solution to a problem I do not have. I don't know of one case where a "bungee wing of death" killed anyone. They will be perfectly fine for your class. An instructor might recommend something else based on a personal opinion, but I doubt you will find one who will say those wings will kill you and not to wear it.

[DA Aquamaster]

The perceived issues with the OMS bungeed wings were things like difficulty orally inflating, a tendency to force air out if the wing got a hole, etc, but with redundant floatation it's a moot issue and has died down to a large extent.

If you are using a dry suit, double check to ensure you are not over inflating the suit in doubles to offset the greater negative swing. Letting the wing carry the load in doubles and keeping the suit minimally inflated may help.

[FW]

Slüdge touched on the issue. You should ask the instructor you are considering. If he/she is dead set against bungees, either get another instructor, or try to figure why you can't use a different style.

Have you tried moving the various wings to different holes? that will make a big difference in trim. Heavier or lighter fins make a big difference too. I have to use heavy fins in backmount, and light ones in sidemount.

Whatever you, don't even consider removing the bungees from the OMS wing. I tried that, and it flopped around like a sick Manta ray

[john844]

Yes, we tried moving both wings and tanks to different holes just in case our perception of how they affected trim was scewed. If we moved the tanks to the lowest hole towards my hips and the wing up closest to my shoulders, that adjustment is maxed out to correct head heavy trim, right? One thing we didn't try was moving the backplate lower and raising tanks up close enough to manipulate valves.

I think my fins are on the heavy side already. They are SP Jets. Are others out there more negative than them?

Ok, I will admit that I considered removing the bungees from the OMS wing. I am glad you stopped me from trying that one.