Editing Hull classification symbol (section)

== National Oceanic and Atmospheric Administration hull codes ==
* R: Research ships, including oceanographic and fisheries research ships
* S: Survey ships, including hydrographic survey ships

The letter is paired with a three-digit number. The first digit of the number is determined by the ship{{'}}s "power tonnage," defined as the sum of its [[shaft horsepower]] and [[gross tonnage|gross international tonnage]], as follows:
* If the power tonnage is 5,501 through 9,000, the first digit is "1".
* If the power tonnage 3,501 through 5,500, the first digit is "2."
* If the power tonnage is 2,001 through 3,500, the first digit is "3."
* If the power tonnage is 1,001 through 2,000, the first digit is "4."
* If the power tonnage is 501 through 1,000, the first digit is "5."
* If the power tonnage is 500 or less and the ship is at least {{convert|65|ft|m|abbr=off|sp=us}} long, the first digit is "6."<ref>{{cite web|url=http://www.corporateservices.noaa.gov/ames/administrative_orders/chapter_217/217-108.html|title=National Oceanic and Atmospheric Administration (NOAA) Home Page|first=US Department of Commerce, NOAA Office of the Chief Administrative Officer (OCAO). Elias|last=Abunassar|website=www.corporateservices.noaa.gov}}</ref>

The second and third digits are assigned to create a unique three-digit hull number.