By a decade at least. This guy has artwork of this stuff dating back to 2003.
And he's not the only one. Konoekihei has artwork (post #1132245) showing that he's been turning ships into girls since 1994.
considering the sailors always refer to ship as "her", if we want to trace it even further I believe we could find one in 14th centuries
β. Battleship Kongou
γ. Armored Aircraft Carrier Shinano
δ. Aircraft Carrier Unryuu
Chain letter with bad luckα. Armored Aircraft Carrier Taihouε. Aircraft Carrier Shoukaku
ζ. Heavy Cruiser Atago
Question: Which American submarine sank the Imperial Japanese Navy ships of the upper section? Choose them from the lower section and link the points of the upper section to the points of the lower section properly.
(2005, Mil.homeip.net affiliated school)