I went to Puerto Rico with my boyfriend this spring break, and it is a very good place to visit, especially the Bio bays. Puerto Rico is located in the east of the Caribbean, and there has plenty of beaches. The local people speak Spanish, but you do not need to worry. Most people could speak English, and they are very kind. I really want to recommend you the most attractive and amazing place in Puerto Rico —- Bio bay.
There are five Bio bays in the world, and three of them are in Puerto Rico.The brightest one is in the south of the Vieques Island, so I went to this island. There is a company which has a special glass boat named Kayak, you can row the boat and also watch the fluorescent fish flow from the bottom of your boat. The price should be around $50, and here is their link: http://viequesadventures.com/ Also, there are plenty of other companies to choose.
If you feel too much trouble to the Vieques Island, you could go to the Fajardo Island which is the second brightest island to see the Bio bay, but there has more tourists than the Vieques Island. After we called booking, as a result, a lot of companies are fully booked because it was a peak season. If you want to play in the peak season, you had better make the reservation in advance. Also, taking electric boat is a lot better than rowing boat by yourself because the fluorescence place is far away from the shore, and you will feel more comfortable. However, rowing boat by yourself is more interesting and challengeable. We chose rowing boat by ourselves, and we had a lot of fun.