danvolker is always going to suggest Palm Beach - it's what he does...

We think they pay him...lol
I've included links to things I talk about after each section since I have them all bookmarked.
Grand Cayman has nice beaches. It's also
very expensive both staying, diving - 2/$100 boat dives is standard, and eating except for some local options. Seven Mile Beach is a nice stretch of sand but the diving there is farther offshore - some operators have flat bottom boats and will pick you up right off the beach. Most of the others offer a free shuttle to their boat in one of the nearby marinas. You can do Cayman more reasonably if you rent a condo or stay off the water, eat at local spots or the U.S. chains - there's a Hard Rock, Burger King, Subway etc. There's also two semi-AI's - Sunset House and Cobalt Coast - meal plans are optional. You can also do quite a bit of good shore diving there to save money. You'll need a car to get around from Cobalt Coast it's pretty far north.
Cayman Islands Scuba Diving Resort
Cayman Resort | Vacation Packages from Cobalt Coast
Cayman Islands | Caribbean Vacation Packages, Honeymoon Caribbean
Scuba Shore Diving Site Listing for: Cayman Islands, Caribbean
Equally nice and pricey but smaller is Turks & Caicos. Grace Bay is often rated the nicest beach in the world - and priced accordingly. I think the diving there is even better than Grand Cayman - we saw more larger stuff there. But we did a liveaboard - doing day trips from Providenciales (Provo) would require 45min. rides to the best sites - West Caicos and French Cay. There's little to no shore diving off Provo, the reef off NW point is slightly too far out. There's also Grand Turk, it's a lot smaller but there's a major cruise port there. There is a wall there that's shore accessible but IDK any details.
Beautiful by Nature - Turks and Caicos Islands - Turks and Caicos Tourist Board
The East Side of St. Thomas also has some nicer beaches. The diving there is mostly shallower out in the cays and off St. John nearby. South of Charlotte Amalie there's a lot of wrecks. There's a couple of decent shore dives but you'd need a car to access them. IIRC staying on St. John is quite a bit pricier than St. Thomas also - we rented condos in a complex near St. Thomas's East End - you'd need a car in that area though. There's two or three dive operators nearby as well - one at Coki Beach, one in Red Hook and one at Sapphire Beach resort. There's also Bolongo Bay, it's more or less an AI dive resort on the east side also. We spent a day or two in Charlotte Amalie transiting thru, if I was going to spend any time on St. Thomas it would be
elsewhere. It's a big cruise port and pretty much every resort we saw in town was fenced with gated security.
If you stay on the East End it's possible to day trip over to St. John - afaik there's only one or two dive operators on St. John now. No personal exp. but my friend's nephew owns there. I think Trunk Bay is more of a snorkel than dive spot - shallow for a long way out. From St. Thomas there's a car ferry all day.
Wreck Dives St. Thomas USVI Scuba Trips Guided Snorkeling Packages
Coki Dive Center | St Thomas US Virgin Islands | Diving Certification Lessons
Red Hook Dive Center | Scuba Diving in St. Thomas US Virgin Islands
Bolongo Bay Beach Resort | The Caribbean's most entertaining beach resort, USVI
S T J O H N U S V I . C O M - Ferry
I've never been but the consensus from what I've read is that Jamaica diving is a step or two down - some of the reefs are pretty fished out.
You might look at Curacao also. It's the same great diving as Bonaire - on the same reef. One advantage it has over Bonaire is there are some nicer beaches there. Most of the beaches are also shore dive sites with onsite rental operators. It's easier to get to - more major carriers fly there - and less expensive than Bonaire since it's the major container port for the region. There's diving in town but the better dives are farther west in more remote areas. An affordable option if you don't mind the 45min. drive back to town (for most things) is All West Apts. in Westpunt. Their shore dive - Playa Kalki/Alice in Wonderland is among the best I've done on either island. We did 22 dives on Curacao - only one was by boat. It's mostly easy entry, low current diving. The reef parallels the shoreline so it's hard to get lost.
We stayed two places on Curacao. One was My Dream Apts. - a nicer newer small complex (8 units) in the resort area of Lagun. It's near nothing except the Playa Lagun divesite. A few minutes north is Playa Jeremi - a top snorkel site listed on Frommer's and other lists. It's also a good shore dive. And a totally isolated beach, we were the only people there all morning. My Dreams cost me $85/nt. for a 1 bedroom apt. with full kitchen - except cooking was limited to a cookplate and microwave. They have WiFi and the ocean front units look down on the water 60' below so no beach. Mt. view is $65/nt. Definitely need a car to stay/dive out there.
Later we moved closer to town to Piscadera Bay. Stayed at Piscadera Bay Resort. A 2 br. condo - not waterfront but water view was $125/nt. Plus cleaning and electricity charges. Mine was $175. Full kitchen, private deck/yard - gated security. Across the street is the Marriott and the Hilton. Both have dive operators, casinos and an average shore dive. There's a couple of nearby restaurants (Denny's and better) and a beach bar within walking distance. Centrum market two miles away for groceries. Dining on Curacao was no more than other reasonably priced resort destinations. 10 minute drive from there to downtown.
We moved into town to do more non-dive things like shopping downtown although we did the Tugboat and Dolphin dive from there. And drove back west 15mins. to Varsenbaai - good dive - avg. local beach.
..:: All West Apartments & Diving, Curacao, Netherlands Antilles ::..
Curacao Travel- Caribbean, Curacao, Dutch Caribbean
http://www.mydreamapartments.com/Englishindex.html
Piscadera Bay Resort
Curacao Beaches - Caribbean Holidays
Scuba Shore Diving Site Listing for: Curacao, ABC Islands
hope this gives you some options, PM if you have more specific questions.