For quality underwater (waterproof) headphones for the CTX3030, you're down to one choice: Detector Pro Greyghost. These don't have an in-line volume control - only the dry-land version does. So, the choice is easy, unless you find someone to modify a headphone and add the correct waterproof connector for the CTX, which is a possibility. I use the GG headphones and they are good enough. Detector Pro is a good company; they stand behind their product.