20,000 Leagues Under the Sea takes you on a voyage that traces the steps of Jules Verne's reclusive character, Captain Nemo. Although it borrows elements from previous Disney underwater rides, it is a new attraction and will be a fresh experience to anyone riding it for the first time.
The queue area is hard to miss. It is a spiraling staircase that is a centerpiece of sorts for Mysterious Island. The last part of the queue is indoors, and while it is themed nicely I personally enjoyed the outdoor portion of the queue which offers some great views of the Mysterious Island scenery from a lower perspective.
Disney theme park fans might see the full-scale replica of the Nautilus submarine parked in the middle of Mysterious Island and think this is a submarine ride in the old-style Disney tradition. Not so. You are not riding in the Nautilus, but rather a mini-sub called the Neptune. These vehicles hold 3 groups of 2 people, one group on each side and one in the front. Unfortunately, the vehicles are cramped and not very comfortable. The windows are positioned so that you need to crane your head down to get the best view. The lucky couple riding in the front of the vehicle have the best vantage point; the side windows are positioned in such a way that they block some of the sightlines. Also, once the vehicle door is closed you're in close quarters with 4 other strangers, and although everyone is looking out the windows, it still felt a little strange, sort of like if you had a stranger stuck in the same ride vehicle with you in the Haunted Mansion.
If you've been on other Disney theme parks' submarine rides, the ride scenery here will look familiar. Kelp beds, schools of fish, sunken ships, a giant squid, and finally a trip through the lost city of Atlantis. The attraction is narrated throughout, although it is entirely in Japanese.
Because you are (supposedly) deep beneath the ocean's surface, there is little light which makes it tough to see all of the details. The ride designers added a smart little counter for this: a spotlight. Each seating station has a joystick in front of the window, and when you hear a bell ring the spotlight for that station lights up and you can point it in whatever direction you chose using the joystick. This adds to the fun and makes it more enticing to ride multiple time and uncover the details you missed on previous rides.
I mentioned the problems with the ride vehicles, but ironically one of the cool things about this ride is the interior of the vehicles. They are finely detailed, and brought to life with animated gauges and sound effects. In fact, you may spend about as much time looking around the insides of the vehicles as looking outside.
I have to say that I initially did not care for this attraction but after riding several times it grew on me. Despite the ergonomic problems of the ride vehicles this attraction is beautifully designed, has interesting special effects, and a multitude of small details that make you want to come back and see everything. Wait times for this attraction vary widely, and if the wait time is more than a few minutes I would strongly recommend coming back later in the evening when the lines tend to be much shorter.