For rookies and veterans, it can be tough to know which island to visit and which place to stay.If deals and perks play into your vacation decision making, the unexpected bonuses at these hotels -- from free kayaking lessons to massages overlooking an underground lake -- might help make up your mind.$100 resort credit (Westin St. John Resort & Villas, St. John)At this posh property astride a crescent-shaped beach on Great Cruz Bay, guests who volunteer a few hours of their time can earn a $100 resort credit good at any of the hotel's facilities.Through a program offered by the Friends of the Virgin Island National Park, interested guests are transported to the nearby park, where they help maintain trails and ruins or pick up debris on the beach.In return they receive a $100 credit to play with back to the hotel.Westin St. John Resort & Villas, 300 Chocolate Hole, St. John, U.S. Virgin Islands; +1 866 716 8108; $229-$569 per night; the hotel is currently undergoing a renovation, so some features may be temporarily closed or relocatedFree water sports lessons (Regent Palms, Turks and Caicos)This all-suite hotel on stunning Grace Bay Beach has amenities galore, including an infinity pool with Wi-Fi and complimentary loaner bikes.Our favorite perk is the sailing, paddle boarding and kayaking lessons included in the resort fee.Already a player?Then you'll appreciate that the equipment is free to use, as well.Regent Palms, Princess Drive, Grace Bay Beach, Providenciales, Turks and Caicos; +649 946 8666; from $499 per nightAqua butler (Ritz-Carlton, Grand Cayman, Cayman Islands)The crystalline waters of the Caribbean are right outside the doorstep at the Ritz-Carlton, Grand Cayman.Guests can take advantage of the location when they nab one the hotel's free aqua beds or aqua lounges that float in the surf just off the beach.Serving you at your watery perch is the aqua butler.You can pick up the nearby coconut phone to request delivery of complimentary sunscreen and magazines or food and drinks.Ritz-Carlton, Grand Cayman, Seven Mile Beach, Grand Cayman, Cayman Islands; +345 943 9000; from $399 per nightOutdoor movies (Grand Lucayan, The Bahamas)This beachfront hotel located 70 miles off the coast of Florida (which, of course, is also technically in the Atlantic, although the regions are often lumped together) has plenty of diversions, from two 18-hole championship golf courses to a Vegas-style casino.The best feature may be the movies shown on a big screen by the pool on Friday and Saturday nights.Popcorn is provided.Grand Lucayan, Sea Horse Road, Lucaya, Grand Bahama Island, The Bahamas; +1 877 434 2996; from $209 per nightSpa in a cave (Grotto Bay Beach Resort, Bermuda)How often can you brag about a massage in a 500,000-year-old cave?For an additional $20, guests of Grotto Bay's Natura Spa can pay to have their rubdown among the ancient stalagmites and stalactites of Serenity Cave, where the treatment table overlooks a crystal clear underground lake.Grotto Bay Beach Resort, 11 Blue Hole Hill, Bailey's Bay, Bermuda; +441 293 8333; from $209 per nightWell-stocked library (Carlisle Bay, Antigua)Forgot to pack your iPad?No worries.Carlisle Bay is among the growing number of hotels to house a library on site.Decked out with fiber optic lighting that changes color throughout the evening, the cozy room has a couple of couches along with bookshelves crammed with several hundred books.Choices range from classics such as "Treasure Island" and "The Lady in the Lake" to miscellaneous selections like "The Superior Person's Book of Words" and "How to Be a Bad Birdwatcher."The library offers a paperback swap.Carlisle Bay, Old Road St. John's‬, Carlisle Bay, Antigua; ‬+268 484 0000; call for ratesHand-rolled cigars (Westin Puntacana Resort & Club, Dominican Republic)This swanky 200-room resort on the scenic far eastern end of the Dominican Republic is brand new but already drawing rave reviews.One of the features most often hailed is the Cigar Bar & Lounge, which not only stocks local and exotic smokes, but a selection of premium rums and Dominican coffees.A specialist is on hand to hand-roll cigars in front of guests.Westin Puntacana Resort & Club, five minutes south of Punta Cana International Airport, Playa Blanca, Punta Cana, Dominican Republic; +809 959 2262; from $308 per nightVersailles-inspired gardens (One&Only Ocean Club, Bahamas)This former private estate is postcard pretty, particularly the ornate terraced garden that leads to the equally picturesque beach.Modeled after the grounds of the famous Château de Versailles, the garden includes elegant statuary carved from Carrera marble and an actual 12th-century Augustinian cloister, purchased from William Randolph Hearst.It was transported from France and reassembled on site piece by piece.One&Only Ocean Club, 1 Casino Drive, Paradise Island, Bahamas; +866 552 0001 or +954 809 2150; call for rates(CNN)ANN.Az