If you own multiple bands, the band used on embarkation day is the only one you can use for the duration of your sailing.
DisneyBand+ & More – Frequently Asked Questions
Q:
Can I use more than one DisneyBand+ throughout my sailing?
A:


Q:
Can I use more than one DisneyBand+ throughout my sailing?
A:
If you own multiple bands, the band used on embarkation day is the only one you can use for the duration of your sailing.