FAS plus upgrade onboard

[dbrown84]

has anyone recently upgraded to FAS plus while onboard?  I've read posts where folks thought it was possible to upgrade if you do it within the first 2 days.  I'm going to have some OBC on my next cruise and I pretty much never had charges to my account.  So, I'm thinking of things to potentially spend it on.  It's non-refundable OBC, so no go on the DSC.

[stefmaia]

There will be a desk either in the atrium or next to the restaurant reservation desk on embarkation day. You can also go to guest services any time on the first day to upgrade. Both of these methods will allow use of your OBC.