FAQ

Decompression:

What decompression model does MV-Plan use ?
What are Gradient Factors for ?
What are the limits of MV-Plan ?

Languages:

What languages does MV-Plan support ?

Installing:

What is Java ?
Will MV-Plan run on an Intel Mac ?
Will MV-Plan run on a PDA ?

Other:

Why is MV-Plan free ?
Can I download the source ?

 

What decompression model does MV-Plan use ?
MV-Plan uses the Buhlmann ZHL-16B decompression model with m-value gradient factors for extra conservatism.
What are Gradient Factors for ?
Gradient factors are a mechanism to introduce conservatism on top of the Buhlmann model. Essentially they represent a percentage of allowable over pressurisation of the theoretical tissue compartment(s). So a GF of 100% means standard Buhlmann, a GF of 0% means that no compartment is allowed to go above ambient pressure (not very practical).
The methodology proposed by Eric Baker proposes a starting gradient factor to be applied to the first deco stop, and an ending gradient factor to be applied to the final stop, with a sliding scale in between. Typical values are 30-80, meaning the first stop is 30% of maximum overpressure, the last stop is 80% overpressure, thus implementing an initial "deep stop" and a measure of conservatism for the last stop.
MV-Plan limits the GF to 90% because Buhlmann never intended divers to use 100% of his maximum over pressure as it represents the point where 5% of divers get the bends.
Further information can be found here
What are the limits of MV-Plan ?
MV-Plan is limited to:
- 100 m depth
- 100 minutes dive segment times
- 0% to 90% gradient factors
- 1.6 bar oxygen partial pressure
These limits are imposed because of basic common sense - i.e. the validity of the model is questionable beyond this range. If this presents a problem to you and you wish to experiment with plans outside of this range please email me.
What languages does MV-Plan support ?
MV-Plan supports language files which allow translations to most languages. Currently there are French and Italian languages included in addition to English.
If you would like to help add your language please email me. This involves updating a text file with translated strings, generaly a couple of hours work.
What is Java ?
Java is the computer language and runtime environment invented by Sun Microsystems. It is widely used on large systems and mobile phones, and it allows a program (like MV-Plan) to run on many different types of computers without modification. This drastically reduces the amount of work to support Macs, Windows and Linux.
Java programs require the runtime environment to be installed first. Most computers already have the runtime environment pre-installed, but it may need to be updated to the latest version. See the manual for installation details.
Will MV-Plan run on an Intel Mac ?
Yes. Mv-Plan is a Java program so is independent of the processor. It will run on any OS-X V10.3+ Mac, Power PC or Intel. It requires the Java Runtime to be up to date.
Will MV-Plan run on a PDA ?
No. MV-Plan requires Java Standard Edition runtime. Generally this is not available for PDAs which can run a cut down mobile edition. It would be possible to make a PDA version, but that would be another project !
 Why is MV-Plan free ?
MV-Plan was written as a personal project so that I could experiment with m-value gradient factors.
A commercial version of MV-Plan implies a level of support and warranty that I am not able to give. Hence the best solution is to make MV-Plan available free to the diving comunity.
 Can I download the source ?
Yes. The Java source code for MV-Plan is available for download under the GNU General Public License.
You are encouraged to took at the source code and re-use it for your own projects. If you are interested in contributing to the on-going development of MV-Plan then please email me.