Sold out Excursions

[sherylc]

Just booked an Alaska cruise for next month on Millennium (after jumping ship from RCCL’s new policies and port arrival times).  One of the tours I’m hoping to book only had one spot available and now shows “check onboard” after we grabbed that spot. Has anyone seen it go back to available to book if someone happens to cancel? Or once it fills up, does it stay as “onboard” only for booking even if there are cancellations? Just wondering if I am wasting my time checking back frequently for a spot to open. (It’s a helicopter tour which I know tends to sell out quickly and I started process very late due to switching lines).