Cancelling a Shore Excursion without penalty?

Our cruise leaves this Thursday and I am having 2nd thoughts on one excursion - what is the latest I can cancel it without a penalty?

Nevermind

Our cruise leaves this Thursday and I am having 2nd thoughts on one excursion - what is the latest I can cancel it without a penalty?

72 hours before sailing to get a credit to your credit card. 48 hours before the excursion to get a shipboard credit.

Thanks ;)