No. However, RCL strongly encourages its tour operators to adopt sustainability practices and to become GSTC Certified. In addition, moving towards 2020, RCL will give preference to sourcing tours that are GSTC Certified and to those that have made progress towards certification, when quality, price, and availability are equal. Tour operators that obtain GSTC Certification will also have the benefit of being listed as a “sustainable tour” upon completion of their certification.