One other idea that may or may not be possible. Could you add a button/link/window, whatever it's called, that allowed divers to add a short dive report? If that option had the required fields of current, temp, visibility, and time, you could use that data to refine your predictions based on how a past forecast held up to actual conditions. I really know nothing about the process you use to put an app together so this may not be feasible. Anyway, it's just a thought.Your comment is very insightful and I'd like to use your ideas for my project. Another person also shared (in an interview) that the rating is something that they would find helpful, so I will be pursuing that direction. I can post my prototype and then can share my more refined design in a few months.
Good luck! Glad you found the previous ideas helpful. Let us know how it turns out.