In Tomorrowland, the Phantom Boats holds the record for being the shortest Disneyland attraction. Operational since opening day on July 17, 1955 and later closing in August of 1956. When it closed, the attraction's waterways were moved and the attraction was both redesigned and renamed.
The Motorboat Cruise would go on to exist for over three decades, moved and re-imagined because it was problematic. The Phantom Boats smoked, were loud and overheated constantly. It also became incredibly expensive to operate. The fan on the boats ended up requiring a cast member to operate for two passengers.
Disneyland would learn from this early failure and re-imagine this entire landscape by creating a new body of water, a new boat ride and the first kinetic energy location of Tomorrowland. The new and improved Motorboat Cruise would replace the Phantom Boats and share the space with two versions of Autopia, the Skyway Buckets and the View Liner. Later a second water attraction, the Submarine Voyage would take over the same space.
Growing up in Los Angeles in the 70s/80s we visited Disneyland on a regular basis and often after school, before "Annual Passes".