When aboard a Coast Guard or other military vessels, you shall remain covered in all areas except the wardroom. Customarily, there will be pegs outside the wardroom to hang headgear. 

BTW, In the military a hat is referred to as a "cover".

For more information, see the Auxiliary Manual and the Auxiliary Courtesy and Protocol Guide http://hdept.cgaux.org/pdf/Courtesy%26ProtocolGuideMAY2013.pdf

Reviewed and updated by BC-UMK on 29 Sep 15