I tried to book every couple of hours from the time I got up in the morning. The site opened for booking at exactly at the correct time (3:00 pm my time). I booked and paid for my 3 most wanted excursions and then went back to book some more. (We are on board for 39 days with 37 port days.). I picked the rest of my optional tours but when I went to the cart and tried to pay, the dreaded wheel just kept going round and round. I decided to go back and book the times I wanted for the included tours. Then I tried again--dreaded wheel. I noticed a "chat box" and used it. The woman was very helpful and managed to book all but one sold out tour for us. I paid though the chat box and got confirmation by email.
After I received the email, I checked my MVJ and the excursions were still in my cart and showed I hadn't paid. I then deleted the items in the cart. I check again and magically they appeared as booked in my MVJ.
Good luck to everyone.
Cynthia