Hello Aquariums,
Your question here about "watermarking" caught my attention because when I had my previous forum I encountered a similar situation as you describe; additionally I enlisted the help of Alexander Ebert of Woltlab regarding the issue of "watermarking" in general, as well as some specific concerns I had with Watermarking.
Due to how "Watermarking" is set up in the Woltlab Forum Software which controls this feature, I decided the best thing for me was to completely forget about using the built-in Watermarking features.
Instead, of those items or photos I wanted "watermarked" for my Forum/Gallery, I did my "watermarking" with my stored computer files
regarding any photo I wanted to bear a "watermark".
This allowed me complete control over just those photos I wanted watermarked, and those which I did not want "watermarked".
TIP for you:
Additionally, from a strictly legal standpoint when this watermarking issue came up I thought I had better contact my attorney.
As it turns out, he suggested I be very careful regarding the whole issue of watermarking.
You can learn much about the legal issues involved regarding this topic by doing some searching on the internet, or, perhaps through your attorney if you have one.
RuffSeas