Bruce uses a GoPro Hero 9 Black to record video when he's at the beach. But the sound gets terrible when the camera gets wet, How can he improve that? There are underwater microphones, but he will need the weatherproof pass through door. But weatherproof isn't waterproof. So that will likely not work. GoPro's MediaMod mic may be the best choice. But again, only weatherproof, not waterproof.
Check out Bruce's YouTube Channel - Oceanside Trenchcoat Guy.