Based on the title "big water" and the context of the excerpt you provided, it suggests that the story might involve elements of nature, exploration, or survival. However, without more specific details from the story, it's difficult to determine the exact genre. If the story includes elements of futuristic technology, extraterrestrial beings, or speculative science, it would be classified as science fiction. If it includes magical elements or mythical creatures, it would be fantasy. If it revolves around a quest or journey, it could be adventure. If it includes suspense or unresolved questions, it would be mystery.
Given these definitions, if you believe the themes align more closely with speculative ideas about the future or advanced technology, then science fiction is the correct choice. If it involves magical or supernatural aspects, then fantasy is more appropriate.
Please consider the themes and specific elements of the story you have to choose the best fitting genre. Based on general assumptions, the best fit without further context will lean towards adventure if it involves exploration of big water. However, if scientific aspects play a significant role in the story, it could be science fiction.