Antiqua and Guam were pretty neat places, but I was extremely fortunate to have Pulled two tours in Bermuda and my last in Hawaii. For the best beaches, I would have to go with:
Bermuda: (1) Horseshoe Bay and (2) Jobson's Cover - both South Shore
Hawaii: (1) Bellows Beach (former AFB) and (2) Waikii
Nowhere, except Bermuda, can you experience the soft, powdery, pink sand of those beaches - "down de road, mon". ('66-'69 and '74-'77)
"Most unusual beach: Punaluu Black Sand Beach, Big Island of Hawaii ('78-'81)
I agree with Dee about Bermuda beaches, how ever "pawpaw beach" in Palmetto Point, Eleuthera was by far the most beautiful, uninhabited, beach I have ever enjoyed. I slept after many mid watches on that beach while the family swam and gathered shells. What a wonderful place.
Chuck