swdw,
The harbors in any port are never clear. But I can tell you the rest of the Pacific during the sixties was pristine. We stopped and had a few swim calls during my WestPac in '69. believe me it was that clear. I was a diver and torpedoman on the USS Segundo SS-398, and you could be on the surface, look underwater and see the keel of the boat.................It was awesome.....