My advice is don't even both trying to ride Nemo right after rope drop. All 3 days we were there Tues, Wed and Thur, everybody headed that direction, there was a 2 hour wait before 9:15! Wait until later in the day. The line will go down to 45 to 1 hour wait.
If you are in the front of the line at the gates at opening, the wait at Nemo will not be 2 hours or 45 minutes. It will be only a few minutes. That is the reason for doing Nemo first.
I would modify the above advice to say that if you can be in front for Nemo, that is a good option. But it requires you to get to the gates early. Not sure how early this time of year. We were there 40 minutes early in June.
If you cannot get to the gates early enough to be one of the first in, then disneyfaninaz's advice to wait until later in the day sounds like good advice to me.
I've read a lot of trip reports. I've also read a lot of threads after searching Nemo. I am still confused about the best route to take from Main St. at rope drop to get me to Nemo fast.
If I am on Main St. at the rope, I am to line up on the right of the rope. But once they drop the rope, I notice there are two ways to go around Matterhorn. Most people say not to go through Tomorrowland. So does that mean I go to the left of the Matterhorn? Not the right? Am I making this too hard?
The confusion is that there are three possible routes to Nemo.
1. The first is the direct right into Tomorrowland after Main Street
2. The second is to pass the Tomorrowland entrance and head towards the Matterhorn (to the right of the castle). When you get to the Matterhorn turn
right. This is actually also part of Tomorrowland. The actual entrance to Nemo is right there when you reach the lagoon.
3. Same as #2 but when you get to the Matterhorn turn
left. This takes you around behind the Matterhorn. This is part of Fantasyland.
If you are there at rope drop, Option 2 is the way is to go. Option 1 is never a good choice. Option 3 is the best choice if you are there fairly early but are not one of the first, and still want to do Nemo first. Since the line for Nemo snakes around behind the Matterhorn towards IASW, Option 3 will take you to where the back of the line has grown by that time.