Diving into the ocean, a lighthouse with a broken lamp must cross the Mariana Trench to warn a naval ship trying to find its way home.

Imbue the lighthouse with a character flaw e.g. fear of lightning that will be overcome by the end of Act 2. Also, the inciting incident should be clearer and by that I mean an event that has never happened to the lighthouse until now. What is it about this particular ship that made the lighthouse dive into the ocean? Include more stakes, for instance, a typhoon heading their way or an enemy submarine.