Amber Arambula

Is this an excursion booked through Royal Caribbean?  If so, they'll wait.  If not.... you may be on your on with this one.

I book and cancel a lot of cruise planner purchases.  So many I started a spreadsheet to track them. 
Amex posts the refund on the date of the refund, usually around 4 days later.  Visa back dates the refund to the date I cancelled the item but they don't post it until 5 or 6 days after the cancellation.  Sometime I need to look back at the date of cancellation to find my refund on Visa which is classified as a "return" as opposed to a refund.  

Mine took about 5 business days, it was a Capital 1.

That's one way to look at it, @mom2mybugs ?  

If you have a credit card but want to budget ahead, just overpay the credit card and have a negative balance.  That would be the same thing without having to constantly settle the cash amount on board.  Jane

I’d be most worried about having to wait in that seemingly endless line of cash people on the last night. Having to pack is depressing enough, waiting in line is worse. 
If you didn’t want to wait until Onboard you usually can go in and update your set sail pass with the credit card information. 

You can change to a card when you board.

if you do switch it to a card - be very mindful to check your balance during your cruise.  you don't want to get hit with the cost of another cruise on your bill because of a lot of charges ?  have a great cruise!

With a cash account no deposit is required. On a typical 7 day cruise you can charge up to $500 before being required to pay the account down. On shorter cruises I think the limit is $300.

The way I’ve always had it explained is that you have to deposit money and draw through that. And if you hit that it’ll stop letting you charge to your shipboard account. The last night of the cruise you’ll have to wait in line to settle up and get any remaining funds back. At that time they’ll lock your account to any more charges.