Day cruises from San Juan or Fajardo

We will be in PR during the third week of May. First time for our friends, not for us. Looking for a day cruise to Culebra or Vieques, a group thing, not a private charter. Any help? We have done day trips from St John to the BVI, and from Tortola to Jost, and in SXM. But I can't find anything like that in Puerto Rico. Am I just not looking in the right place?

There are a few boats running out of Puerto Del Ray Marina in Fajardo. You also can take the ferry for less than ten dollars each way from Fajardo and just rent a golf cart for the day on Culebra.

http://www.islaculebra.com/puerto-rico/culebra-ferry-schedule.html

http://www.viator.com/tours/San-Juan/Cul...2&aid=g7976

http://www.jerrysjeeprental.com/our-fleet-rates.htm

Ha! I love this part:

"For reservations call
Fajardo (787) 863-0852, (787) 860-8618
800-981-2005 - sometimes they answer and then again, sometimes they do not

All times are given WITHOUT warranty"

Open some days; closed others.