I got your email. This forum is the proper place for discussion.
The Bar30 Depth/Pressure Sensor has a relative accuracy of 204 cm in freshwater. I would like to order the Bar02 Depth/Pressure Sensor which has a relative accuracy of 4 cm in freshwater.
Be careful, the datasheets for the 30BA and the 02BA differ in what they specify (absolute accuracy vs relative accuracy, ie precision).
The Bar30 measurement may differ from the true pressure by +/-100mbar in the long term, but consecutive measurements are very precise (within a 1~2 centimeters). So you can consider this +/- 100mbar as a constant offset, and ‘tare’ your measurement once before going in the water.
For this project it is helpful to know to a high accuracy where the vehicle is.
In summary, we use the Bar30 on our vehicles, and it is well-suited for the application you describe.
I was hoping that I could change something maybe in the software driver to make it compatible with ArduSub since the connector for both sensors are the same.
It is possible to adjust the sensor driver to accomodate the 02BA part. You will have to do this on your own, however.