Speaking as a regulator technican, this is not true. Any downstream second stage with the appropriate amount of spring rate in the second stage and specified intermediate pressure acting against the downstream seat will breathe as good as any other second stage, provided that the cracking pressure is set correctly. The reason that most octos breath noticeably harder is because they are specifically set to a higher cracking pressure from the factory to avoid freeflow. Even adjustable second stage octos are set to a higher factory cracking pressure by most manufacturers than their primary counterparts. If you recommend something, please be sure you are correct as to why you are recommending it. The only things that dictate work of breathing are second stage orifice diameter, diaphragm size, the mechanical advantage of the lever, and the rate of the spring acting to close the low pressure seat.
Long hose for a new diver
- Thread starter jtpwils
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Speaking as a regulator technican, this is not true. Any downstream second stage with the appropriate amount of spring rate in the second stage and specified intermediate pressure acting against the downstream seat will breathe as good as any other second stage, provided that the cracking pressure is set correctly. The reason that most octos breath noticeably harder is because they are specifically set to a higher cracking pressure from the factory to avoid freeflow. Even adjustable second stage octos are set to a higher factory cracking pressure by most manufacturers than their primary counterparts. If you recommend something, please be sure you are correct as to why you are recommending it. The only things that dictate work of breathing are second stage orifice diameter, diaphragm size, the mechanical advantage of the lever, and the rate of the spring acting to close the low pressure seat.
I am - she's not. My daughter and I did a discover class together. That thread is here.
I'm going with a DSS BP/W with DUI Weight & Trim and she's getting a SP Glide Plus jacket style BC. When she outgrows that, my other daughter will take it.
We're both going with MK17 1st stages and G250v seconds. I'm going to wear another G250v in the "std" config and she's going with a R295 Octo. I decided that "typical" would be better for her for commonality reasons and that it would probably be better for me due to the simpler deploy, vis-a-vis snorkel, and also for "finding the reg" skills. Easy enough to change the hose later.
BTW - the LDS said the same thing as Slonda828 regarding the octos, at least when I questioned him on the 295 vs. 395. He said that they have the same internals, and that as far as he could see the 395 just had a metal purge button but they shared the same internals and it's not worth paying more for the 395. He also said that both are high quality regs and that he just tunes them to be less sensitive to prevent free flow.
You have made a good choice, in my opinion.
Long hoses have one purpose, to get divers out of a restricted overhead envioronment while sharing air. Aside from that, long hoses are a pain and potentially dangerous.
In basic open water, you are taught in an OOA or air sharing situation, the donor and receiving diver should be close enough to control each other's buoyancy. With a panicked out of air diver, the last thing you want is that diver five or seven feet above you heading for the surface as fast as he can swim. Believe me, you will have no chance of controlling that diver and you will be taking a ride to the surface yourself.
I am all in favor of a bungeed octo, makes perfect sense and I believe the only reason it has not been adopted as standard practice in open water classes is the certifying agencies are worried people will shy away from sharing a primary hose directly from another diver's mouth.
From a practical point of view, long hoses can be prone to floating, especially during dives with a lot of surge. They also tend to allow your second stand to smash on the floor. They are, of course, more expensive (price a Miflex 7 foot hose).
As I said, there is one good reason for a long hose, getting single file out of a cave or wreck.
This is, of course, just my opinion.
Jeff
If one of my students asked me if they could start their training using a "long hose" I'd have the following reactions:
a. Great -- glad you made a reasonable choice; BUT
b. FOR THE CLASS, hold off, use a shorter hose (40 inch?) on your primary -- i.e., one that does NOT wrap around your neck.
And there is one simple reason -- that (stupid) snorkel you are required to actually use during a PADI OW class (this is assuming this is a PADI OW class -- although my friend, a NAUI CD says NAUI is actually more strict about snorkels than PADI). I know that a "real pro" (like Thal) can use a long hose and a snorkel but us mere mortals find the combination to be nasty.
By using a 40 inch hose on your primary, along with a bungied backup, you will still donate your primary (GOOD IDEA!) but you won't have the issues related to getting it wrapped around the (damn) snorkel (not to mention the issues related to someone saying, What Have You Got There?). It is a very simple step from using a 40 inch, open water setup, to the longer 5 or 7 foot hose.
I use a 40 inch hose on my primary for my "confined water" teaching (along with an AirSource inflator/reg combo) but switch over to the more traditional long hose/bungied backup for open water (because in open water I don't have to demonstrate any skills therefore I put my snorkel in my pocket).
But then I live and dive in the PNW and I guess we are a little weird up here.
a. Great -- glad you made a reasonable choice; BUT
b. FOR THE CLASS, hold off, use a shorter hose (40 inch?) on your primary -- i.e., one that does NOT wrap around your neck.
And there is one simple reason -- that (stupid) snorkel you are required to actually use during a PADI OW class (this is assuming this is a PADI OW class -- although my friend, a NAUI CD says NAUI is actually more strict about snorkels than PADI). I know that a "real pro" (like Thal) can use a long hose and a snorkel but us mere mortals find the combination to be nasty.
By using a 40 inch hose on your primary, along with a bungied backup, you will still donate your primary (GOOD IDEA!) but you won't have the issues related to getting it wrapped around the (damn) snorkel (not to mention the issues related to someone saying, What Have You Got There?). It is a very simple step from using a 40 inch, open water setup, to the longer 5 or 7 foot hose.
I use a 40 inch hose on my primary for my "confined water" teaching (along with an AirSource inflator/reg combo) but switch over to the more traditional long hose/bungied backup for open water (because in open water I don't have to demonstrate any skills therefore I put my snorkel in my pocket).
But then I live and dive in the PNW and I guess we are a little weird up here.
Doesn't having a 40 inch primary hose kind of defeat the purpose of having a streamlined setup? I bet if you turn your head too far left it snags on your shoulder. One of the big things about the long hose is that it is streamlined. A 40 inch hose hanging out there off of your primary is...sloppy. Isn't that kind of a lot of trouble to go through when you could just use a 26 inch primary hose and a 40 inch octo hose? My profile picture show a 26" primary and 40" secondary setup. For open water diving, and any professional (non-technical) duites it works great. It is about as streamlined as you can get if you route it correctly. Still, whatever floats your boat man. I'm not the one who has to dive it.
Wouldn't a 40" would be long enough to route under your right arm?
I'm an heretic
I dove such a setup for a while - miflex with an elbow on the regulator - not sure about the exact length but it was something like 40.
It works really well: out of the way, really easy on the mouth, etc... Not as convenient for sharing as a 7ft, but good enough for OW. It's less of a mess on a boat as the 7ft as well. You do have to pay attention to clip it under the bungeed secondary if for any reason the secondary is not in your mouth as you clip it.
LeadTurn_SD
Contributor
Yes. To prevent "pull", some folks use a "swivel" that attaches to the 2nd stage and points down (it is actually a fixed 90 deg. elbow fitting, not sure why it is called a swivel
).Some bigger folks can also route a 5' hose under their right arm. I'm pretty tall (a bit over 6'4"), and alternate routing my 5' Miflex hose under my right arm (like a 40" would) or under my right arm, across chest, behind neck (like a 7' hose). The 5' is a tad short to route in the traditional behind the neck manner, but I can get away with it becuase the Miflex will accept a tighter bend than most other hoses and still not pull (to much
).Best wishes.
Edit: Whooops, my bad ptyx, didn't see your next post, you knew all this stuff, Sorry.
CalgaryDF
Contributor
I currently have a 40" primary hose with an elbow and a shorter octo hose. Both go under my arm and keep out of the way during the dive. With the 40" hose and the elbow sharing air is really easy when I donate the primary because the elbow prevents the hose from going into that weird s bend that always seems to be pulling the octo out of the recipients mouth. I've found the 40" hose gives lots of space while still being close enough to stay in contact.
This setup came standard when I bought my setup (Sherwood Maximus) and I've loved it.
Similar threads
