Culebra visit....advice please

It is accurate that you should get to the terminal in Fajardo to purchase tickets for the ferry to Culebra that early.  The ferry is not always reliable or on time, and has been known to be sold out. Another option is to take a small plane over there either from San Juan or Ceiba.  The cost is more, but it's a sure thing, dependable and much more efficient time wise.  Once on the island, you can hail a taxi to take you to the beach or rent a jeep.

I seem to remember that taxi was a fix cost something like 2 dollars but is is a shared taxi. Ferry is like 2 dollars each way unless it has gone up in the last two years. Seniors are 1 dollar I believe.
If they have changed let me know.

If it is in your budget, I recommend flying instead. Flights are cheaper if you take a taxi across town from SJU to Isla Grande Airport (ISG), or find your way (taxi is about $100) to Ceiba on the east coast & fly from there. Just going across town to ISG halves the plane fare so it is totally worth the cost of the taxi ($20 or so, but that you can split between up to four or five riders).

Flights from ISG to Vieques or Culebra follow the north coast of the island with either views of the ocean or mountains.