Another ship naming question (REAL ships this time)

[Schnitte]

When did systematic usage of ship name prefixes, like HMS and USS, start? What navy was the first to equip every vessel with such a prefix?

[Darwin_s_Finch]

For U.S.S., the practice was first made official by President Theodore Roosevelt on Jan. 8, 1907:

In order that there shall be uniformity in the matter of designating naval vessels, it is hereby directed that the official designation of vessels of war, and other vessels of the Navy of the United States, shall be the name of such vessel, preceded by the words, United States Ship, or the letters U.S.S., and by no other words or letters.
–Executive Order 549, 8 January 1907.

[sewalk]

It was started, like nearly every other great naval tradition, by the British. It was used to differentiate private ships from those owned by the Crown. Its use predates the American Revolution, but I don’t know by how far.