Just to flesh it out for the aircraft photogs who are not computer types.
1. Log into the Member Section at https://www.airport-data.com/member/
2. On the left hand links click on "Account Info" (right below Member Home).
3. CHANGE #1 of 3: Under "Display Options" select a nonzero multiple-of-3 number (previous poster's example is "6"), enter it under "photos on each page (visitors' view) and click Update.
4. CHANGE #2 of 3: Same page select a nonzero number (previous poster's example is "10"), enter it under "...(member's view)" and click Update.
5. CHANGE #3 of 3: Under "Watermark Options" at the bottom section, set opacity to be nonzero (15% is recommended) to display airport-data's watermark on the image. They ARE hosting this for free, and providing a forum for free, and not even have annoying ads or popups... so this is one way to return the favor. This is not required to have your pics visible again, just an opportunity to return the favor.
Thanks for the solution, thanks to those who prodded to get the solution, and thanks to A-D for hosting these.
Note: I take no credit for anything in the solution, only in attempting to step-by-step it so those who are not so savvy can do it as easily as the rest.
Best regards,
Ehud Gavron
FAA Commercial Helicopter Pilot and all around tech guy
Tucson, Arizona, US -- KTUS