Hi,
I would like to suggest an improvement for the Volume Module.
Would be great if we could calculate the volume of sediment between two defined surfaces. I have been studying how the sand ebb delta of Patos Lagoon (South Brazil) has changed over the last century, so overlapping two nautical charts I could calculate the volume of sediment the has been added or has left some specific area, identifying erosional or acretional process. To make this, there is a need to define the range of neutral balance. In some works I define the range for accretion or erosion on +-20 cm, in others +-5cm is ok, so the user must have control on that.
Here is an example of my works.
I think it wont have troubles to add this.
The neutral or clear spaces, is a 30 cm range between the subtraction of the 2 charts.
Calculated the net sediment volume, erosion volume and accretion volume
I don´t know if I was clear on my explanation.

Nice idea. Although we have already got plans to add features for calculating differences in volumes between maps, I like the idea of producing a new map that shows the differences graphically. I'll see if we can include something like that!