Hey everyone...I just wanted to throw my 2 cents worth into a subject that has been brought up a few times on this board. It seems that some people are under the false impression that the Prism rebreather will go under if something should happen to the owner, Peter Ready. Let me point out a few facts that have been conveniently left out of the whole picture...1) Peter's wife Sharon, who is an active participant in the company and avid rebreather diver, would be more then capable of taking over the research and development within the company...2) Peter has assembled additional, active people within the company who are also more then capable of taking over...3) IT'S OFFICIAL.. The U.S. Navy HAS bought the Prism for their divers after over a years worth of research on ALL rebreathers on the market. Peter is working closely with Navy researchers on production and development. So if something did happen to Peter, I'm sure that our Navy would not bag the whole project. ( I'm curious how the Inspiration scored on the testing)........I apologize if I ruffled anyone's feathers over this. It just appears that Inspiration divers are using this idea as a marketing ploy against Prism. I personally believe that both units are very good units but if my kid came up to me tomorrow and said "DAD, I want an Inspiration Rebreather but don't worry its safe..only 12-19 people have died on it in the last 1.5 years". My response would be "NO WAY"..
Prism rebreather
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DrySuitDave
Contributor
Well, how many more Inspiration units are being used compared to Prism's?
Until you do an analysis and take such into account, raw numbers are problematic.
Switching gears, it is good you posted such info. I took a look at the Prism and I really liked the unit's compact size and some teaser I heard about a piezo electric scrubber.
If the Navy gets involved, it is bound to get even better. Do they ship units now with the computer generated fairing used on their web site? And what about computerized controls?
Until you do an analysis and take such into account, raw numbers are problematic.
Switching gears, it is good you posted such info. I took a look at the Prism and I really liked the unit's compact size and some teaser I heard about a piezo electric scrubber.
If the Navy gets involved, it is bound to get even better. Do they ship units now with the computer generated fairing used on their web site? And what about computerized controls?
The prism isn't a bad design but it has 2 serious flaws (in my opinion) which I don't see why they don't fix..
1 the user has no control over the electronic setpoint (choosing what the high/low values are) underwater
2 the setpoint changes are done automatically and the user can't override this..without shutting down the electronics and controlling manually.
I frequently change my setpoints depending on conditions.. If I'm having a very relaxed no exertion dive I generally raise the high setpoint, but if the dive become strenuous I back the high set point off a bit) I also vary the setpoint according to depth... in shallow water where trying to maintain a high setpoint can effect buoyancy I usually set it to 1.0 (unless I am decoing), I use a setpoint of 0.7 on decent which the actual is usually higher, and at depth 1.3-1.5.
I dive/teach an Inspiration (and it does have its flaws) but at least the user has full control (within reason) of the PO2 setpoints.. (can be set from 0.5 to 1.5 with an actual PO2 of 0.4 and 1.6 generating alarms) On the prism if you wish to use other setpoints the only real option is to shut off the electronics and fly it manually.
There aren't enough Prism's out there to compare dive accident numbers. The only rebreather that has been around that I have never heard of having an accident is the mk 15/15.5/16 and its probably due to the strict training policies implemented. I haven't seen a report that any of the Inspiration fatalities have been to equipment malfunction, in fact if you look at the reports most fall into 2 basic categories recently certified users with little experience or those idiots that start doing dives well beyong their CCR training.. just because they used to do the same dives on OC..
I don't think the Inspiration is perfect but a properly trained diver should have no problems at all... I have over 200 hours on my unit (so far down to almost 100M (327 feet) on mixed gas and and 65M (~210 feet)on air ) and have had only had a few minor issues (all cell related which will happen to any rebreather), nothing that was a real problem(remember the inspiration has 3 cells), and the unit gave the appropiate warnings..
I am getting another rebreather - Infinito which is probably the best unit available but I will continue to use my Inspiration when I travel, I rather take the chance of getting a $6k rebreather ripped off than one that cost almost $20K.
1 the user has no control over the electronic setpoint (choosing what the high/low values are) underwater
2 the setpoint changes are done automatically and the user can't override this..without shutting down the electronics and controlling manually.
I frequently change my setpoints depending on conditions.. If I'm having a very relaxed no exertion dive I generally raise the high setpoint, but if the dive become strenuous I back the high set point off a bit) I also vary the setpoint according to depth... in shallow water where trying to maintain a high setpoint can effect buoyancy I usually set it to 1.0 (unless I am decoing), I use a setpoint of 0.7 on decent which the actual is usually higher, and at depth 1.3-1.5.
I dive/teach an Inspiration (and it does have its flaws) but at least the user has full control (within reason) of the PO2 setpoints.. (can be set from 0.5 to 1.5 with an actual PO2 of 0.4 and 1.6 generating alarms) On the prism if you wish to use other setpoints the only real option is to shut off the electronics and fly it manually.
There aren't enough Prism's out there to compare dive accident numbers. The only rebreather that has been around that I have never heard of having an accident is the mk 15/15.5/16 and its probably due to the strict training policies implemented. I haven't seen a report that any of the Inspiration fatalities have been to equipment malfunction, in fact if you look at the reports most fall into 2 basic categories recently certified users with little experience or those idiots that start doing dives well beyong their CCR training.. just because they used to do the same dives on OC..
I don't think the Inspiration is perfect but a properly trained diver should have no problems at all... I have over 200 hours on my unit (so far down to almost 100M (327 feet) on mixed gas and and 65M (~210 feet)on air ) and have had only had a few minor issues (all cell related which will happen to any rebreather), nothing that was a real problem(remember the inspiration has 3 cells), and the unit gave the appropiate warnings..
I am getting another rebreather - Infinito which is probably the best unit available but I will continue to use my Inspiration when I travel, I rather take the chance of getting a $6k rebreather ripped off than one that cost almost $20K.
DrySuitDave
Contributor
Isn't the Inspiro a SCR unit?
I remember the Oceanic Phibian which has a niced integrated CCR and dive/deco computer. I do not like the additional hoses and pressure guages of the Inspiration. It is an old and new technology clash. Didn't stop me from ordering one!
I hear the VR3 wrist computer is slated to have hoseless sensors for some new controls.
I remember the Oceanic Phibian which has a niced integrated CCR and dive/deco computer. I do not like the additional hoses and pressure guages of the Inspiration. It is an old and new technology clash. Didn't stop me from ordering one!
I hear the VR3 wrist computer is slated to have hoseless sensors for some new controls.
read carefully *** INFINITO ***, its by a company called powerbreathe in milan. The system is fully closed. its the most redundant made.. it was designed by stuart clough formerlly of the ut-240 and some others.. it also does real time decompression and has been tested to operate at 250 meters.. (about 810 feet) the deco computer supports, nitrogen, helium, neon and I believe argon and hydrogen as inert gasses.
it supports multiple diluent supplies for optimal mixes for all depths..
The pressure guages on the unit really only come into play when you are first operating the unit to check the supply and if you want to know how much gas you have in bail out.. during a dive you you very little diluent - a bit for buoyancy and the initial makeup volume of the loop, 150psi (10 bar) or less out of a 20cf cylinder is pretty common.
an experienced CCR diver under normal dive conditions uses about 1 liter of o2 per minute, the inspiration uses 3 liter cylinders so its about 20 bar per hour (300 psi of 20 cft) approx 2 cu ft per hour...
it supports multiple diluent supplies for optimal mixes for all depths..
The pressure guages on the unit really only come into play when you are first operating the unit to check the supply and if you want to know how much gas you have in bail out.. during a dive you you very little diluent - a bit for buoyancy and the initial makeup volume of the loop, 150psi (10 bar) or less out of a 20cf cylinder is pretty common.
an experienced CCR diver under normal dive conditions uses about 1 liter of o2 per minute, the inspiration uses 3 liter cylinders so its about 20 bar per hour (300 psi of 20 cft) approx 2 cu ft per hour...
DrySuitDave
Contributor
Why would a high po2 setpoint affect bouyancy when it is just a mix setting rather than total volume setting, and you only have 1-2 breaths on your counterlung anyway?
at higher setpoints at shallow depths, the controller is frequently trying to inject o2.. many rebreathers alter the time they leave the o2 "on" depending on the differance between current po2 and the setpoint. When you get your Inspiration youll see how much it can vary from the setpoint on the surface and in shallow water, once you at about 50feet the variations is very little from setpoint. another thing that many don't consider you cant always get 100% oxygen, I know in many places the best you can get is 96%, which is CONSIDERED 100% oxygen by many standards, but on a rebreather your loop volume will be getting greater as time progresses since youll always have some gas that isnt used on each injection. at shallower depths low setpoints are much easier to control.. This is the main reason on all dives I do a loop flush at 20 feet with "pure" o2 and now buoyancy control is quite easy, as loop volume decreases youll become slightly negative and then just inject a little o2, to make you neutral again, deco stops are very easy to maintain in this manner.. Since you are above the normal 1.3 setpoint the controller will not do any injection for you (until you get to a 1.3).. on long deco stops youll notice your loop volume is getting greater since the loop is no longer 100% o2 from your offgassing.. I flush the loop usually every 5-10 minutes (more at the beginning of the deco)
When doing my deco calcs, I tell the deco software to continue on using 1.3 as the setpoint not 1.6 to allow a margin of error for the fluctuating PO2... I usually have all deco done with last stop at the 20ft stop, and stay a few extra minutes at 10ft then slow ascent on final 10 ft, if I'm also using a multi gas computer at this point (10ft) I'll back its PO2 down to 1.0..
When doing my deco calcs, I tell the deco software to continue on using 1.3 as the setpoint not 1.6 to allow a margin of error for the fluctuating PO2... I usually have all deco done with last stop at the 20ft stop, and stay a few extra minutes at 10ft then slow ascent on final 10 ft, if I'm also using a multi gas computer at this point (10ft) I'll back its PO2 down to 1.0..
While you are correct, the navy has purchased prism units, the navy's goals are different from what most TECH divers want and need. The navy wants a simple as close to "ideot proof unit" as you can get, navy divers don't spend countless hours playing with there gear as most of us do.
I currently dive a prism and am am happy with the units performance. However there are several problems 1) the lack of control under water 2) the secondary display's are very tempermental 3) because the owners of steam machines are holding the navy so high on the hill, recreational divers are put on the back burner, in short the customer service is horrable, and is sentered around money not doing right by the customer.
Anyone who says there unit has been tested against ALL rebreathers available is LYING.
The Navy has NOT tested ALL units available
The rebreather that has won the most praise in recient months has been the megaladon. This information comes from DIVERS who have OWNED: Cis-Lunars, Buddy, Prism, Mark 15.5, BMR 500's
The infineto sounds good, but I don't know if there are ANY in the states.
Hope this helps
JP
I currently dive a prism and am am happy with the units performance. However there are several problems 1) the lack of control under water 2) the secondary display's are very tempermental 3) because the owners of steam machines are holding the navy so high on the hill, recreational divers are put on the back burner, in short the customer service is horrable, and is sentered around money not doing right by the customer.
Anyone who says there unit has been tested against ALL rebreathers available is LYING.
The Navy has NOT tested ALL units available
The rebreather that has won the most praise in recient months has been the megaladon. This information comes from DIVERS who have OWNED: Cis-Lunars, Buddy, Prism, Mark 15.5, BMR 500's
The infineto sounds good, but I don't know if there are ANY in the states.
Hope this helps
JP
DrySuitDave
Contributor
For a photo of a Prism Topaz for sale on E-Bay, click here
Here is the text description in the ad:
THIS IS A FULLY CLOSED ELECTRONICALLY CONTROLLED REBREATHER FOR SALE. THE US NAVY CURRENTLY DIVES THIS UNIT. I HAVE ALL OF THE LATEST SOFTWARE AND DISPLAYS AVAILABLE. THIS COMES WITH ALL OF THE STANDARD EQUIPMENT PLUS 2 OMS 45'S, 3 SPARE O2 SEN., A CUSTOM MADE SS ENCLOSURE. ANYONE BIDDING KNOWS WHAT THEY ARE GETTING. GOOD LUCK.
Here is the text description in the ad:
THIS IS A FULLY CLOSED ELECTRONICALLY CONTROLLED REBREATHER FOR SALE. THE US NAVY CURRENTLY DIVES THIS UNIT. I HAVE ALL OF THE LATEST SOFTWARE AND DISPLAYS AVAILABLE. THIS COMES WITH ALL OF THE STANDARD EQUIPMENT PLUS 2 OMS 45'S, 3 SPARE O2 SEN., A CUSTOM MADE SS ENCLOSURE. ANYONE BIDDING KNOWS WHAT THEY ARE GETTING. GOOD LUCK.
There is one Local to us (NY) and its been around for a while..I first saw it about 2 years ago. In a few weeks there will be several more locally..
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