This show had great intentions when it first aired and was a Science FACT show expect for some of the ship technology. It used many naturally occuring events underwater to drive it's episodes. The CG computer animation SUCKED and you never really got to know the ship...the muddy fake underwater stuff was done so poorly that it was laughable.
When producers saw ratings slide they changed the focus of the show and introduced Aliens and Bang! the show got higher numbers. This started the decline of the show as it went more Sci-Fi and started with more silly alien stuff.
It's too bad that they didn't do more real underwater filming. As cheesy as some of the Irwin Allens show were (Voyage to the Bottom of the Sea) There was a realness to the Seaview Sub. It was a character in the show with the Flying Sub just about the coolest thing I had ever seen. This show lacked that realism. Don't do a show about underwater if you never really go there!!