Fajardo and the East coast, that includes Culebra and Vieques Island, is the boater's eden as it is the door to the Eastern Caribbean. From Fajardo, most boaters travel/sail to the USVI, The British Virgin Islands and the different small islands-nations that Westward and Eastward Islands have. Fajardo has Marina Puerto del Rey, Sunbay Marina and Villa Marina. Humacao has its Marina de Palmas.
Traveling from those east points is easy and secure as you will find boat traffic and the US Coast Guard servicing between USVI and Puerto Rico. Also there are some cays on the northeast part of the Islands that you can also enjoy.
(Photo of Palomino Island in Fajardo ¬©PuertoRiKo.Com)