I picked up a Tesoro Sand Shark about 6 months ago, and I'm just now getting it ready for first use at the beach. It has "Bilsom Warrior" headphones with turqoise color earpieces. Are these underwater phones? It's been awhile, and I can't recall what the seller told me about them...I bought this in a lot with other detectors and equipment, and I didn't write down the particulars. Now, I'm not sure if these are waterproof.