@@leoliu2958 You put on diving gears when you go underwater, if you can hire a guide, it shouldn't be a problem even for people without any swimming experiences. But yeah, it's definitely weird for a surfing coach to not be able to swim..
To my knowledge, any kinds of watersports, the basic requirement is to know how to swim. I really don't understand how she got to pass the course to be a surfing. instructor.