This would be a wonderful party idea for anyone! It would be best to do it in the summer, for a birthday or just for fun! I recommend doing it in a large grassy backyard or field or park.If you have a pool you already have a head start! DECORATION: Go crazy with decorations!!! Use turquoise and light blue crape paper to decorate the outside of a house, fence, gate and the general party scene. Add a tropical flair with bright colored party balloons. You can even let some non-helium balloons loose for playing with when guests arrive.(Colors like orange pink yellow and green are great!)Hanging Christmas lights gives a good atmosphere to any party. If you are planning on serving food at your party grilling is always fun. Dont be afraid to have lots of variety and color when your serving snacks. If you have an extra table or pick nick table, use it as a FOOD/SNACKS table. One fun recipe is filling a half pineapple with chicken salad. Fruit is always good: try filing several trays or bowls with different types of fruit try some tropical exotic fruits Star fruit, Guava, Pommelo, even hibiscus. decorating your food table can be a colorful table cloth, and you can buy or make your own centerpiece I find parrots are colorful and go along with the tropical theam well(: As for grilling you can do the traditional hot dogs/hamburgers but to make  a fun alternative you can make kabobs. You can put on bacon, ham, chicken,any meat you want! You can also add pineapple, mushroom, and mini tomatoes for color and flavor. Corn cobs are also great for grilling! Here is a fun desert that is extremely delicious: Take a medium sized orange and cut out the top as you would a jack-o-lantern, scoop out the insides, add one to two scoops of orange sherbet,then add a kiwi slice covering the top, freeze them until you are ready to serve them.GAMES AND FUN: Setting up a slipn'slide is great fun for kids. Even a simple sprinkler system does a great job of keeping kids entertained.You could try having kids play duck duck goose around the sprinkler.That's always a hit! Fill a kiddie pool with water balloons and let the kids create there own games. Balloon stomp, limbo, those are all popular choices. For girls decorating flip flops is easy and affordable. On oriental trading.com they have rubber ducks for sale. If you can find tropical themed  ones those are always great party favors.