I have long hair myself. And especially when it is colored. I know how you feel. Usually I would not shampoo my hair that clean if I knew I am going diving because the oil from itself from the root it works well when you comb it from the bottom up. I would toss my hair upside down and start at the very bottom by using a wide tooth comb. Don’t use a brush. And before you go diving. Make sure you are applying a lot of gloss shine which it also helps it to comb it easier when you come out of the water. It always works for me all the time. Good luck and have fun on your trip.