We are planning to head to Culebra Island on July 7 (Sat), I read a lot of articles saying that it's not easy to get the ferry ticket. I am afraid we cannot get the ferry ticket that day,so I am just curious if we cannot get to the island that day. What other attractions or activities that we can do that day. We will go the El Yunque and Liquillo Beach on July 6 (Friday), so we want some other things to do as back up. Thank you for the advices. Hopefully we can get to the Culebra as first priority.