The Coast Guard proposes to amend its merchant mariner training and manning regulations to incorporate the requirements of the 2015 and 2016 amendments to the International Convention on Standards of Training, Certification, and Watchkeeping for Seafarers, 1978, as amended. These requirements will implement the training and manning provisions of the International Code of Safety for Ships Using Gases or Other Low Flashpoint Fuels, commonly known as the IGF Code; create national endorsements for vessels utilizing gases or low flashpoint fuels; and implement the training and manning provisions of the International Code for Ships Operating in Polar Waters, commonly known as the Polar Code.