If my data is all corrected to full-pool elevation of a reservoir, and the reservoir is 20 feet low, do I enter a negative number in the water offset? (-20) ?
I'm getting ready to try out V2 and this is the main change I have been looking so forward to in V2. Hopefully I can get it going.

Yes - the value you enter in the water level offset field will be added to everything that forms the map project; tracks, boundaries and spot depths (new in v2). So in your example, a water level offset of -20 will reduce the depth of the finished project by 20.

In most maps, you will still end up with isobaths for the negative values, and your shoreline would end up as -20. With the new editing features in RM, you can fic your map in a few ways - e.g. select all isobaths < 0 and move them over to the land layer, or change their colour to a land colour, or use a "fixed depth palette" from 0 with a land colour for < 0.

I should just add to that the point that you do need to regenerate your map after changing a water level offset. The offset is applied to map source data, not to any map components that have already been generated.

Sounds good. I assume it changes all the project data, but not the raw data that's already earlier corrected to full-pool (offset) for reference, so I'll always have that data? In the case of offseting the original SL2 tracks, I entered a positive number to bring the water level up to full-pool elevation.

It just applies the offset as it uses the raw data, so no raw data will be affected. I think your approach of adjusting to full pool is a good one, and just adjust the water level offset as required. Another alternative is to duplicate your project a few times (you can make a copy via the right-click menu in the asset list) and then maintain a few different versions with different water level offsets (using the same source data).

Matt wrote:
Sweet! Making a quick copy and changing different offsets will be awesome. Used to do that with the old-school Dr. Depth. I'm importing the first 1332 tracks as I type this! I'm fully upgraded and registered.

Good luck! You should be able to just migrate your old RM1 workspace, if you have one with the tracks already imported. This would probably be a bit quicker!