I went last month, the cruise leaves for 5 or 6 hours at a time. When you go on for the first time they gave me a coupon for free entry during the next 30 days. It was fun!
You can book more than one night. Reservations are by phone or you can login into their website.
Reservations are recommended, not required. You can book multiple cruises. If you sail the AM cruise, you can sail the PM cruise, that same day, for free.
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