Free flow and the Oceanic Omega II

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NU2DIVING

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I recently purchased a PX 2 1st stage with an Omega II second stage. I bought them used. I am completely happy with the breathing performance of this combo. However, It was driving me crazy how bad this thing free flows at the surface. It is a pain in the neck or better yet a pain in th O2 consumption trying to keep this thing from free flowing. I have to keep my thumb over the mouth piece or every time a wave comes...pshhhhhht. Or heaven forbid I let go of it to remove my fins or grab the ladder to get back on the boat or just accidentily drop it. Does anybody else experience this? If so what do you do about it? Do you just always put it back in your mouth if you need the use of your hand on the surface? I am still working on my air consumption under water so every once in my tank helps. Not to mention that after I surface I get a little worried about draining the tank more than it should be. It can be a bit of a chore to find that thing if you drop and it is free flowing and jetting around underwater.

Any thoughts,

Mike
 
Firstly, congratulations on your choice of a new sport. I used an Omega II for about 8 years and really loved the performance. The only thing I didn't like about it was that it breathed a little wet, and I found myself having to clear it more than I wanted to. It may have just been a servicing issue, or some small part that might have fixed the situation (diaphram, etc.), but I just got aggravated one day while taking pictures and switched to a very dry breathing reg.

Never had any troubles with freeflowing though. Since you bought it used, I would suggest you have it serviced by a qualified Oceanic technician. He can probably tune it down a little, or replace some inexpensive parts and you should be set. When they work, they work very well. Until you get it serviced, make sure you have the mouthpiece pointed down in the water at the surface, and the front of the reg where the diaphram is pointed up towards the sky. When you have it tuned, don't have it tuned down so much as to make it too hard to breathe from. Your tech will know where to find the compromise between free flow and ease of breathing.

I never realized how loud my bubbles were going past my ears until I stopped using the Omega II. It definitely has some great advantages by being a side breather. You can see better and hear better, and it delivers a comfortable amount of air volume. There are much easier breathing regs out there because the Omega II works on a servo valve, which opens the main valve to deliver air to you on demand. This "two step" process can sometimes be felt by divers who have used several types of regs, but you may never notice the difference.

I am no regulator expert or technician by any stretch of the imagination, but I will try to explain the servo concept. You can find many good threads on this board giving much better descriptions than this one, so try a search. The servo valve arrangement has a negative point being that it is not a "fail safe/fail open" downstream valve system. It is an upstream design. If there is a problem and the servo valve doesn't open, then air supply may be shut off to the diver, instead of the 2nd stage freeflowing. However, modern reg designs are so good that I have never heard of this happening, and I have done many dives with the Omega II. Also, Oceanic regs are almost "bullet proof" and offer years of service and reliability if cared for properly and serviced. They are a great value for the money too. Even the PX2 you have is a workhorse piston design that delivers plenty of air flow.

So, in summary...

Not so good points: wet breather, upstream design, satisfactory breather (not the best), yours needs servicing.

Good points: no bubbles in your field of vision, quieter, streamlined, no jaw fatigue, no right side up (can be used as an octo with the purge valve/diaphram on the left or right side of your buddy's mouth), easy to get parts and service, inexpensive.

Even though I haven't used mine as my primary 2nd stage in over a year, I still use one as an octo (and have another as a backup). Still can't let go of those things!

Finally...you should have yours inspected and serviced. As a new diver, you're going to have issues with air consumption for a while (not to mention buoyancy control-another topic), but remember you can use your snorkel on the surface to conserve air if the surface is calm enough. Hope this helps, and I hope others will follow and give better explanations of the design. Be safe and happy diving.
 
I don't think that it is safe to assume that it needs servicing as there are other variables that could cause this. The most likely inmyopinion is that because the regs is a servo assisted valve, that it freeflows alot easier. The vacuum initiated by the flow of air nearly causes a freeflow on the surface let alone in the water. Try hitting the purge really hard and you will see the blast of air that comes out compared to your octo. The is because they are not the same design. I won't get into the specifics unless you want. But simply put, it needs to be detuned just a little so that it doesn't freeflow. At the same time it will slightly compromise performance. Other options for a cure to this problem is that you could put it on a bungee so that even when not in your mouth it is nearly out of the water. Personally though I try to keep my reg in my mouth until out of the water in case you fall back in or something like that. I wouldn't jump into a service yet but if it needs it by all means go ahead. Hope this helps.
 
I have one and have never had a problem with it freeflowing. the only thing like mentioned is a little bit wet brether...and i do have to clear it every so often but it's not that bad.
 
realdiver7:
The servo valve arrangement has a negative point being that it is not a "fail safe/fail open" downstream valve system. It is an upstream design.

Simply not true. The Omega II (and Zeta for that matter) are both downstream pilots. Take off the plastic reg housing and look at the valve - it's obvious.

The Tekna servo reg (2100 series) WAS an upstream pilot - and had an overpressure mechanism to manage a 1st stage overpressure failure.

Pilot or servo regs can be either upstream or downstream, designers choice.

P
 
rescuediver009:
The most likely inmyopinion is that because the regs is a servo assisted valve, that it freeflows alot easier.

ALL modern high flow second stages will free flow easily - low inhalation resistance (cracking pressure) and huge flow rates are a recipe for free flow. Servo or no servo.

The difference in the Omega is the lack of a "detuning" switch - venturi assist in Scubapro speak - to lessen the sensitivity of the reg. Drop a SP G250 in (full venturi assist mode) if you want to see a good freeflow . . . .

The Omega is in maximum performance mode at all times. Understand this fact and adjust your diving as needed.

P
 
NU2DIVING:
It was driving me crazy how bad this thing free flows at the surface. . . . I have to keep my thumb over the mouth piece or every time a wave comes ...pshhhhhht. Or heaven forbid I let go of it to remove my fins or grab the ladder to get back on the boat or just accidentily drop it.

Some observations from an old fart diver . . . .

1 The transition zone (air/water boundary) will always be a challenge whilst diving. The experience/finesse of seasoned divers can sometimes go unnoticed as they traverse this zone.

2 Newer divers tend to reach the surface and immediately abandon all of the life support equipment they carry - mask off (typically on the forehead), regulator out of the mouth, etc.

3 Experienced divers will RETAIN their mask and reg until well clear of this transition zone . . . keep your mask on and reg in until you are ON the boat, or standing securely out of the surf / wave / current zone.

4 A reg in the mouth NEVER free flows (barring equipment failure).

While boat diving - Keep reg in your mouth as you remove fins, gear to get in the boat. Climb the ladder with reg in your mouth (yes, I've seen people pitched into the drink from the ladder - not pretty).

While shore diving - keep reg in your mouth as you traverse the zone. Remove fins with reg in your mouth. Remove reg only when you are clear of the water - when you are sure your reg will not dangle in the water. Simply loop the second stage hose behind your neck to keep the reg out of the water if you remove it a little early.

The extra air you consume while doing this is minor (typically at the end of the dive, no impact unless you drain the tank).

The safety and enjoyment of your dive will be greater . . .

P
 
pcosens:
ALL modern high flow second stages will free flow easily - low inhalation resistance (cracking pressure) and huge flow rates are a recipe for free flow. Servo or no servo.
P

The servo was designed to have a near zero breathing effort (see poseidon xstream series) as they create the vacuum in the second stage which results in a high flow rate. But when you compare all second stages it always depends on the tuning. That is what will determine the freeflow suceptability.
 
I am still using this reg and love it. I also put the reg back in my mouth when exiting from a shore dive through the transition zone. If you don't do this not only will it free flow but it will get full of sand. A little sand can be a big problem.
 
I don't think that it is safe to assume that it needs servicing as there are other variables that could cause this.

When buying a used reg, I don't think it's safe to assume it DOESN'T need to be serviced.

:D
 
https://www.shearwater.com/products/teric/

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