@ Dale -
I see nothing in the pdf manual that mentions anything about upgrades or updates.
Interestingly, though, and somewhat off topic, the manual does say this:
WARNING: It may be possible to configure Marine Aquarium in such a way that monitor burn in is possible. (This depends on the age of and type of monitor — such as older CRT or newer plasma monitors.) Please use caution and only use the static background settings (auto-panning off) if you are sure that the monitor will not suffer from burn in.
Please read the monitor’s documentation and, if the monitor is subject to burn in, do not run Marine Aquarium in static mode.
Don't know if the pdf is proprietary to Nova or not.