vr3 or shearwater pursuit

[battles2a5]

I completely agree with everything you say here. My question, which leads back to my original post, is how do you know what curve works best for off gassing? Many people say what you post - you can adjust the curve of the deco schedule. I get it. How do you know that by adjusting this curve - your making a better profile for yourself? You really don't. You just just as easily be making a deco profile that is more stressful to your body, and off-gasses less efficiently. Unless you understand all these tissue models, and how they work with your body, you're really just throwing a dart in the dark.

I'm not knocking GF either - in fact I used it exclusively before I bought my X1, as that's what my Hammerheads had in them. However in the Hammerhead, there are 4 or 5 pre-set Gradient Factors built in that the user can adjust. Setting #1 is 10/100, and it goes down from there. I use mine on #3, which is 25/85, and that seems to work great. There is also a "custom user setting" where you can put whatever you want in there, and even in the manual, it tells you - if you don't have a doctorate in GF, then don't mess with the custom setting.

I understand what you are saying. I don't think there is a magic bullet for knowing how to make adjustments. Everyone's physiology is different. Fundamentally, we know which curves work for a given profile so that would be my baseline. From there, I think you have to experiment. If you feel like crap when you get out of the water, then you need to make adjustments. If you feel great you make small incremental changes towards more agressive profiles and get yourself out of the water quicker. If you feel good and are fine w/ the amount of deco you are doing, then just keep diving it. I'm not talking about coming up with an arbitrary set of GFs for every dive, I'm talking about making gradual adjustments as you dive similar profiles until you find out what works best for you. I am perfectly comfortable adjusting profiles based on how I feel after a dive. So to answer your questions, I think you find the right GFs by starting w/ the established baselines and making incremental adjustments from there to suit your comfort level.

 

[Tienuts]

Why Liquivision X1 is much better computer?

Several reasons:

1. The display - Wonderful, bright, and easy to read. It eliminates the need for a backlight in any situation. Often times I have found myself in situations which were not dark, but just too dim to read the display of my VR3 or hammerhead without the backlight.

2. Ease of use - The VR3 is very complicated, and requires a new user to damn near study the manual before using it. I am the customer service rep for the largest Delta P dealer, and I have hundreds of hours on the VR3 - I still get confused when using it. While doing training dives, doing simulated bailout - I have found myself in menu's I didn't mean to get in, and not able to get back to where I need to be. With the X1, it is damn near idiot proof. No icons, no complicated menus. Simple, easy to use, and plain english. Although not recommended, you could dive the thing without ever having read the manual. When in a complex situation, such as OOA, gas sharing or bailout, you need something simple.

3. Software - Have you used the interface for the VR3? Forget the fact it costs an extra $400 - it also looks like it was written in MS-DOS, and functions about as well. The X1 uses V-planner. Ross Hemmingway is a genius programmer, and also responsive to what the divers want and ask for. Many of the changes he has programmed into are at the request of divers. Good luck getting Delta P to answer an email.

Also much smaller, the tapping interface is great and much better than push buttons, and it's robust and solid.

 

[SlowRain]

I assume that you would therefore not consider purchasing a watch or computer that didn't have a battery, such as a solar powered or motion/eco powered watch. Similarly I assume you would not buy an Uwatec Bottom Timer, since the battery cannot be changed, and it would only last 10 years.

In some sense comparing a disposable battery that lasts for 6-12 months, to a rechargeable battery that lasts for five or even ten years isn't really fair. Like you, I won't buy a watch that has a disposable battery that needs to be changed every year, unless I can change it myself. A rechargeable battery is a different story.

The battery in the X1 should have about 30% of its original capacity after 10 years. That equals about 7-8 hours of dive time.


Eric Fattah
Liquivision Products

I think you are on to something...my main watch...An Omega Seamaster Chrono...no battery at all. Laptop computers do use batteries...and the user can change them with spares if they so choose. I don't think a comparison of a laptop to a dive computer is putting apples to apples for 2 main reasons. First of all I will not be potentially putting my life in the hands of my laptop (although that is why we cut tables as a backup in case the dive computer goes south on us). Second...after having used laptops for the last 10+ years (it is my issued computer at work) even if the battery goes south, I can plug the thing into the wall and use it. Even if there is not a wall socket to be found, I go back to the first statment...there is nothing on my laptop that is life saving in nature.

Not here to debate it...as I said it is purely a personal decision. One of my "make or break" selection criteria for a dive computer is that I be able to replace the battery. If I can't...then it is off the consideration table. I am in the medical device industry, specifically contact lenses. When the customer (eye care professionals) or consumers (end users) start to express what they want, and what they consider not necessary we listen and evaluate. The evaluation is how much of the market could we capture by going to the expense of development and execution of what they want either by modification of an existing product line or creating a new product line. If it shows that the effort would be a losing proposition, then obviously we aren't going there. On the other hand, if it is breakeven (preventing loss of competition taking your market share) or we would be gaining market share....we execute. If we don't...our competition will.

 

[Tienuts]

Not here to debate it...as I said it is purely a personal decision. One of my "make or break" selection criteria for a dive computer is that I be able to replace the battery. If I can't...then it is off the consideration table.

That's pretty ironic, considering how common computer failures are due to user-replaceable batteries. Saft batteries have a very high failure rate - I know, as I personally exchange almost 20% of them. Look on The Deco Stop and Rebreather World. Not a week goes by where someone hasn't posted a thread about their VR3 shutting off at depth - in every case, it is a result of a battery issue (Non-UK sized AA battery in a UK sized compartment.) I'm not even counting the incidents where the user does not replace the battery door or the o-ring properly, and the unit floods.

With proper care and maintenance on the X1 battery, it will last the life of the computer. In 10 years, there will be the X15, or something better out. I don't think your battery argument is valid here.

 

[SlowRain]

That's pretty ironic, considering how common computer failures are due to user-replaceable batteries. Saft batteries have a very high failure rate - I know, as I personally exchange almost 20% of them. Look on The Deco Stop and Rebreather World. Not a week goes by where someone hasn't posted a thread about their VR3 shutting off at depth - in every case, it is a result of a battery issue (Non-UK sized AA battery in a UK sized compartment.) I'm not even counting the incidents where the user does not replace the battery door or the o-ring properly, and the unit floods.

With proper care and maintenance on the X1 battery, it will last the life of the computer. In 10 years, there will be the X15, or something better out. I don't think your battery argument is valid here.

Then I would say that by using an improper fitted battery...or not assuring you have replaced the battery correctly that you have a case of operator error. By your quote above...I don't see the VR3 itself being the cause of the failure/problem.

Again...this is a case of PERSONAL PREFERENCE...as I have stated in all my posts on this thread. I like the X1 and the advancements it has made...but it is my PERSONAL PREFERENCE that the computer I own and use allows me to change the battery. If someone has a different opinion then they are entitled to it and I respect their right to make their decision...just as I have made my own.

 

[DANM]

ok everyone let's play nice, i started this thread for info from all of you knowledgeble people for help with my decision, not to start the next coke vs pepsi debate. i appreciate everyones input but don't want to start any arguments. thanks to all. Dan

 

[Tienuts]

Then I would say that by using an improper fitted battery...or not assuring you have replaced the battery correctly that you have a case of operator error. By your quote above...I don't see the VR3 itself being the cause of the failure/problem.

Again...this is a case of PERSONAL PREFERENCE...as I have stated in all my posts on this thread. I like the X1 and the advancements it has made...but it is my PERSONAL PREFERENCE that the computer I own and use allows me to change the battery. If someone has a different opinion then they are entitled to it and I respect their right to make their decision...just as I have made my own.

I'm not arguing personal preference. Go nuts and dive what you like. That's why they make chocolate and vanilla. My post was for the benefit of the OP so he and others can make an informed decision on what computer to get. It's more likely a diver will have a failure of a replaceable battery during a dive, than with a properly maintained rechargeable.