I'm not sure with the current release, but with RM V 2 one can do that very easy (although I have done not yet).

How would you do it? We are currently doing it through a subtraction model in ARCGIS. I would love to be able to duplicate those changes.

I would create two sets of data, each exported as *.shp file or as a kml file.

The next step is depending, in which way you want to use it, on your plotter or PC?

We are trying to do something like this.

I think, you could import two overlays in GE at the same time. These overlays you should generate in different colors and give it a high transparency in GE.

As Hubert wrote: It's important if you want to use a plotter and if yes, what a model. With HDS this is not a problem (pic).

This will not be used on a chart plotter. We use this to create reports based off of changes of bottom type due to commercial activity

ArcGIS has a lot of tools to solve your problems.

That is what we have been been using. I was just wondering if anyone knew of a way

I still do not know, what you want to do exactly.

If you want to visualize it very impressively, you can use a morphing program.
First, create the two times as georeferenced images, then merge the two images with a morphing program. So you get the changes like in a time-lapse recording.

Thanks. We have been testing outputs from the last few years worth of data and it looks like if you import both tracks, it will do an spacial average. The outcomes appear close enough. Now only if I could figure out a way to define the points where it shows different colors.

e. g. raster analysis, with the raster calculator or other tools. The cell grid should be as small as possible or as the user need it.