When in Hawaii, a charter denied my wife diving the backwall of Molokini Crater due to not having their minimum suggested dives (they wanted 25 dives, I believe she had 18 or so at the time and just completed her advanced open water certification while diving in Kona). She was great though and let me dive that morning without her, but honestly, after completing that dive, I didn’t see what the big deal was...yes there was current, but all we did was drift along the wall between 80 and 100 feet...then swam away from the wall into the blue for about 100 feet or so (to prevent the boat from being pushed into the rocks), was a super easy dive. I hit Molokini on a bad day though anyway so she really didn’t miss much, none of the usual big creatures cruising out in the blue.