I was on a great trip this year! I learned about what pH is, salinity, and what many other things are. pH is the amount of acid in the water, or substance. Water has a pH of 7. Salinity is how much salt is in the water. I learned how to detect the visibility of water, But forgot what it was called. There were a couple things I didn't like, though. For instance, we only had about 2-3 minutes to paint. Overall, I liked this trip.