I tried it a few times and the game is either to hard or Im doing something wrong. it feels like pure RNG.
Sometimes I select a point and both submarines arrive nearly perfectly on their own, on others I had 1 sub stopped right in front of the point only for the second to get juggled for 15 seconds.
Then again there are times when I have one stopped right next to the point and when I release it, it instantly gets swept away. While in some other cases one attaches and just chills there for a few seconds, until the other arrives without my help. IDK what I'm supposed to do, trying to stop the subs does not seem to do enough, trying to keep them in sync before they are at the end does not seem to matter because they get knocked about before they can reach the end and stalling at the very end is effectively just waiting until the other one gets to make its way there. And what comes of it is the mechanic of using multiple expeditions does not seem to do much since I'm unable to stall both so at best the second one is RNG to see if they just happen to align.
The art and idea are neat, I just wish the game was clearer about what is expected of me/had some sort of difficulty curve to it.