Hidenobu Yoshimura Instruktor CCR-Cavern Explorer-Hollis Level1 Instructor OC-Advanced-Nitrox-Open-Water-Diver OC-Deco-Diver OC-Extended Range-Diver OC-Nitrox-Diver OC-Sidemount-Diver OW-Nitrox Diver Prism2 Level1