[Aquarena underwater web cam no longer exists. Texas State University which ownes Aquarena decided to tear down most of the amusement park structures and let the area revert back to its natural state which ultimately meant that the underwater web cam would no longer be located there. Aquarena is now known as The Meadows Center For Water And The Environment.]
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Aquarena Underwater Web Cam - Underwater Web Cam

If you can see the image above, it's daytime. If the image is black, it's night time underwater!
On Wednesday, March 26, 2008 at Aquarena Springs - San Marcos, Texas, an underwater video camera was installed near the deepest area of the springs. The "ribbon cutting" ceremony for the new Aquarena Underwater Web Cam was conducted by Dr. Sylvia Earle, Ambassador to the world's oceans. (Dr. Slyvia Earle)
Two video clips about Aquarena underwater web cam are listed below. The first clip gives a few looks at the camera itself and the second clip has some of the Dr. Earle ceremony.
Video Clip 1-FOX 7 Launches Underwater Web Cam at Aquarena Center
Video Clip 2-Underwater Web Cam Unveiled at Aquarena's Deep Hole
Background newspaper article -https://web.archive.org/web/20080429030742/http://www.sanmarcosrecord.com/local/local_story_081114311.html
The dedication ceremony occurred around 2:50 PM. Dr. Earle signed autographs prior to the ceremony. Ron Coley, Director of Aquarena, was the master of ceremonies for the event. Afterwards, Dr. Earle did some brief interviews for the press. Later she was to give a presentation to Texas State University that evening.
The camera sits inside a diving bell as such, inside a clear Plexiglas cylinder a few feet in length. The cylinder is sealed at the top and open at the bottom with the cables running out the bottom to the computer about 60 feet away. It is anchored to the bottom in about 20 feet of water and overlooks the deepest area of the springs, about 60 feet of depth. From the computer, the head of the web cam can be rotated, left/right, up/down. If the perspective of the web cam changes, it is because someone has adjusted the web cam view from the computer.
Details of the camera installation were given to me by diver involved in making final adjustments to the underwater web cam set up prior to the dedication ceremony. The underwater web cam is the idea of Shawn O’Shea from FOX 7, Austin, Texas. The web cam will give an around the clock look at the Springs. At night, the image presented will be black. It is to be seen whether on clear nights with a full moon whether there will be sufficient light to capture an image by the underwater web cam. It appears that adjustments are currently being made to the image refresh rate.
The diving bell housing is an unique concept for an underwater camera housing. It will be interesting to see how the electronics of the camera hold up in a high humidity environment.
Paul Johnston - March 26, 2008
University Scuba Club - The Early Years
Copyright - Paul Johnston - Austin News Story - 2008