Building up your boat is one of the key ways to progress through the game. The Blueprint station is the key to this progress, however it may sometimes get stuck after opening.
If this has happened to you, you will need to close and relaunch your game in order to keep playing. If you haven't triggered an autosave recently by visiting an island, you may lose some progress.
To avoid triggering this issue again, always make sure that the in-game cursor is properly highlighting something in the Blueprint Station menus after swapping tabs. If you close out the menu while nothing is highlighted, the issue is likely to occur again.