We have ~$800 of OBC on our upcoming cruise - and no idea how to spend it all on a 7 day cruise with no sea-days. We have however, pre-booked and paid for some excursions on a CC. Curious if anyone has gone to Guest services and cancelled the excursion while on board - and then immediately had them re-book it using OBC? I assume the pricing is the same? are you allowed to do this?