You will love it! The trips we have done to LC in August have always been great! Unless there is a hurricane nearby (which is actually not that common that time of year in the western Caribbean), the seas are generally VERY calm and very warm in August. It is also the beginning of the slow period for the islands, so the airport is less crowded, there are fewer boats running at the resorts, etc. The trade off is that it can be pretty hot during the middle of the afternoon, but I live in Texas, so that is nothing new to me.