Sea Hunt was shot off Santa Catalina Island, in the Santa Barbara channel islands. According to IMDB there were tropical locations as well, but what I most remember is the kelp, which doesn’t exist in the tropics.
Although the water is colder (52F), the kelp forests in the Montery area are even better. Whaler’s Cove at Point Lobos, in Carmel, is one of the best places I’ve dived. The cove is all granite, with an 80" drop-off at the mouth of the cove.
My cold water diving days are over, however. This is where I dive now:
That’s not me in the picture. That’s a friend of mine.