Long-tail engines are are called Ruea Hang Yao in East Asia where they are very commonly used. They are cheap, easy to maintain and can carry you into muddy shallow water.
Their ancestry is as always ambiguous - from Nazi assault boats, to
Atco which was/is one of England's première lawn mower manufacturers, Atco Boatimpeller came out in 1948/49 checkout http://www.oddjobmotors.com for more info.
check out the history of Long tail motors
First Lontail Engine in the Thames Estuary
first tryFirst Long tail engine on the Thames from Harwood YoHa