I am actually getting married on the Carnival Pride in 9 days. They actually marry you on board by an officiant. All we need is to take our marriage license, but we don't have to get married by a JP before the wedding. If you have any questions about a Carnival wedding I will do my best to answer them. Another great place to get information is theweddingexperience.com. That is who carnival contracts to handle the wedding stuff.
They also do vow renewals.