If you’re doing it correctly, scuba diving is virtually no effort at all, right? But let’s be honest: Even the most gorgeous shallow reef can get a little bit boring on your hundredth visit. It doesn’t have to be that way. For those who want to challenge themselves — through training for the most advanced diving out there, or just by trying something new to you — scuba diving.com offers 15 ideas that will take you to your next level. All you have to do is commit.