Why do I have to enter my Castaway Club ID after I've already signed in to the Disney Cruise Line website?
Castaway Club – Frequently Asked Questions
You’ll only need to enter your Castaway Club ID number one time to access the Castaway Club section of the Disney Cruise Line website. Adding your ID automatically updates your Disney account information.
The next time you return to the site, you’ll only need to sign in using your Disney account email and password to access your cruise information, Wish List and exclusive Castaway Club Member content.