Have you found the tools in Humviewer by right clicking on any of the image panes..??

In a DI image or 2d image in Humviewer...I generally set the "Crop to" setting to the next depth deeper than the actual water depth...this will show more of the water column above the bottom detail in a DI image or SI image...

I think you may be correct about the propwash and weeds in the SI image...

Do you have any screenshots from the unit itself of this same area...??

It is possible to playback that same recording in the HB unit and take snapshots of any point in the recording...

You can even freeze the playback in the HB unit (with the 4way cursor) and open a zoom window on those interesting sections of the display...and then take the snapshot...

Rickie