St. Croix in October

[staciarn]

We are visiting St. Croix (along with St. Maarten, Barbados, St. Thomas, & ST. Lucia) in October.  There are 6 of us in our early 50's.  We will take 1-2 boat/snorkeling trips.  We are looking for other inexpensive excursions or beach trips. Most of us like snorkeling (will bring own equipment) and beach lounging.  What is your best beach to visit to visit if you had only 1 day there.  I would love to snorkel on Buck island - but worried about traveling across the island from Fred to Christian.  Are there reasonably priced Buck island excursions that leave from Fred?  If not, what beach would you recommend going to that we can snorkel, relax in shade (or rent an umbrella)?  How much is taxis or are there any other forms of transportation?  Anything you suggest that you cannot leave the island without seeing?  Thanks for any help?