When you've finished all 10 immersions, the bathyscaphe stops working for the next 14 hours. The earlier you finish these 10 immersions, the earlier the bathyscaphe will be available next time. If the time for immersions runs out in the process, the bathyscaphe becomes unavailable for 14 hours as well. If you start immersions later, next time bathyscaphe will be available later too. With the help of these actions, you can choose when you want the bathyscaphe to be available.