Yes, do it in advance
Yes
Yes, and you can go to any of the Old Town Trolley ticket booths in St. Augustine and let them reserve it for you and save $19 on the price
Yes. The website has a easy way to use the calendar to set available slot times, availability, and reservation options all right there. A day before they called to confirm reservation, and to go over the rules and how things work. We had a group of 5, and were paired up with with about 7 others, but us 5 had our own dolphin to interact with.
Yes definitely plan it in advance.
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