Nuclear Plant 01

I almost missed Nuclear Plant 01 because I decided to defeat the Bealbeach gym leader before going on the boat, only to find the boat was gone after I had beaten the gym. Luckily I had saved just before, so I didn't lose too much, but it would be good if the gym leader was mising until you had gone to the power plant, or at least if it was more obvious that this has to be done before the gym.
Thanks.

Currently this is an optional sidequest so it's not a huge deal if you miss it (although it is one of a couple of chances to catch nuclear pokemon). In the future I think the devs have mentioned that they will be making it mandatory as part of the story.