My library just got a set of Sea Hunt DVD’s . . .
and though I vaguely remember whirlybirds, I can’t recollect it (also losing my memory at the age of 60).
Ah, Sea Hunt! I used to watch Sea Hunt all the time. So much so, that my Dad became so annoyed by the constant sound of bubbles from the SCUBA gear he would go out and sit in the yard whenever the show was on. My favorite episode was when Mike Nelson stepped on a giant clam which quickly closed around his leg and trapped him. This all seemed perfectly reasonable to me, and even likely. Mike's solution, which seemed equally reasonable, if not obvious, was to ignite an underwater flair and stick it into the clam's shell, causing the poor burnt clam to release him. I saw that episode many times.