Vessels that are numbered by the states (see 46 USC section 411) and small, non-registered craft owned by U.S. citizens and not registered in other countries may also hoist a U.S. ensign to show their national character.

The U.S. Yacht Ensign (a variation of the national ensign; see below) is often used in place of the national flag by U.S. pleasure craft when operating within U.S. waters; this flag was legally required for licensed yachts from 1848 to 1980, and the practice continues among all U.S. pleasure craft in U.S. waters by longstanding historical use and custom.

It was first hoisted aboard Commodore Esek Hopkins' flagship Alfred on the Delaware River by Lieutenant John Paul Jones on December 3, 1775.

(Though later, the better documented St. Eustatius incident involving the USS Andrew Doria is traditionally regarded as the "first salute".)

The "boat flags'" formal recognition lasted just four more years however, as President Wilson acting through Secretary of the Navy Josephus Daniels discontinued the practice in 1916 with Executive Order 2390, after which all ensigns were supposed to have the full complement of stars.

[8] The United States Coast Guard flies a unique ensign to show that it has the authority to stop, board, examine, and seize vessels.

On August 1, 1799, Wolcott Jr., issued an order announcing that in pursuance of authority from the President, the distinguishing ensign and pennant for the Revenue-Marine would consist of, "16 perpendicular stripes, alternate red and white, the union of the ensign to be the arms of the United States in a dark blue on a white field."

[9] From 1799 onwards, this flag was used as the national ensign for the Revenue-Marine (from 1894 known as the Revenue Cutter Service) and at the same time, was also flown over Customs Houses ashore.

In 1895, 27 June, Assistant Secretary of the Treasury Charles Sumner Hamlin issued an order that United States Revenue Cutter Service vessels must henceforth carry the national ensign at the main-peak and the revenue service ensign at the fore-peak.

2764 of the revised Statutes, I hereby prescribe that the distinguishing flag now used by vessels of the Revenue Cutter Service be marked by the distinctive emblem of that service, in blue and white, placed on a line with the lower edge of the union, and over the center of the seventh vertical red stripe from the mast of said flag, the emblem to cover a horizontal space of three stripes.

[16] Yachts eligible for the license were initially 20 net tons and over (later reduced to 15 net tons) and otherwise eligible to be enrolled as a U.S. vessel; the license allowed the yacht to proceed from port to port without the formality of clearing customs.

The Secretary of the Navy approved a modification of "the American Ensign" as the signal, and Treasury Decision No.

The United States Power Squadrons (or USPS) is a non-profit educational organization whose mission is to improve maritime safety and enjoyability through classes in seamanship, navigation, and other related subjects.

[23] The U.S. Power Squadrons manual of flag etiquette states, "The preferred location for flying the USPS ensign is the starboard yardarm or spreader halyard.

In April 1776, the Massachusetts Navy adopted, as its flag, a white field charged with a green pine tree and the motto "An Appeal to Heaven."

It features symbols from the current flag and the older one, with a white field and green pine tree.

2, § 3, while Maine's state law says: “The flag to be known as the merchant and marine flag of the State shall be of white, at the top of which in blue letters shall be the motto “Dirigo”; beneath the motto shall be the representation of a pine tree in green color” Me.