20K was a remarkable ride, but unfortunately what made it unique also made it a liability.
I loved it because it was "real" - not that undersea creatures, mermaids and the like were real, LOL, but because you really were underwater (however shallow) and you truly were taking an under-"sea" adventure. All that stuff really was there, under the water with you.
The unfortunate side is the constant maintainance and the difficulty doing it. They had to send divers down there regularly - a huge expense on it's own (divers that could fix animatronics and such - two skills that don't generally go together). (Side note : can you imagine how freaky/cool that must have been? They used to go down at night too...enough to give you nightmares!)
In later years it was closed in the fall seasons for extended periods while the place was drained and the massive amount of work to keep the thing together had to happen. Even before it was left to sit stagnant for a decade, it was already decaying - the show building (where much of the actual ride took place, hidden by rock face) was a mess before they ever even closed the ride.
When they finally did drain the thing one final time last year, the stuff underwater had all but disintergrated. No matter how much they did, it was always delaying the inevitable - underground water tanks with all the complex machinery and show scenes did well lasting in almost 25 years of service (71-94) but there was no way for them to last forever.
One might question why not just do it over, but by the mid-90's this would have been a HUGE expense. We're talking tens of millions of dollars, all to rebuild an attraction that technolgically was dated and would have not been much more interesting had they rebuilt it - there is only so much you can actually do underwater, even in with today's (or the mid-90's) technology.
That said, I do hope that eventually they rebuild a 20K-themed ride at the MK, using the dry-for-wet technology used at Tokyo DisneySea. They have a 20K ride that goes "underwater", but doesn't really - the water effect is actually in the portholes and the show scenes outside the ride "submarine" are actually bone dry. Really simply, picture the portholes as two panes of glass pressed up next to each other, with water and bubbles between the two panes creating the illusion of being underwater. It's quite effective, even if you know what you are looking for.
The revamp of the Subs at
Disneyland is going to be different as well - thankfully they decided to put the money into it, and will be using video projection and sealed glass for whatever showpieces are added. It seems as if the infrastructure was more sound at Disneyland - even though the attraction was older.
So I too wish we still had 20K, but am happy to know that we still will have a true under-water attraction at Disneyland. Hopefully a new and improved 20K will make it to WDW someday - I just fear that since the film isn't starring some animated character that they can hawk merchandise for and create sub-par animated half-hour shows about it may be a long wait.
N.E.D.