C1/D Visa

[immihelp]

I recently was offered a position on a cruise ship as a guest entertainer and was told that I need a C1/D transit visa. I'm not sure if I actually need it because I have a British Passport but also have a U.S. Resident Alien Card ("green card"). I've lived in the U.S. for nearly 15 years and my green card does not expire for 3 more years.

Please could you advise me as to whether or not I need the C1/D visa and/or what steps I need to take to obtain it? Thanks.

[immihelp]

You don't need C1/D visa.