The only surviving Dornier 17 aircraft has been discovered off the Kent coast.
The Luftwaffe bomber was forced to make an emergency landing in the sea after being shot down on August 26 1940 by the RAF during the Battle of Britain.
Only two of the four crew members survived the impact at Goodwin Sands, both becoming prisoners of war.
Last month, a survey commissioned by the RAF Museum at Hendon found that the plane remains largely intact, with only slight damage to the cockpit and windows.
The museum's Ian Thirsk told the BBC it was "one of the most significant aeronautical finds of the century".
The museum hopes to conserve rather than restore the plane before putting it on display. Unlikely as it seems, if this aircraft were ever to appear at auction it could achieve a huge sum, being the only surviving example of its type and due to the unique period of history in which it served.
Nicknamed "The Flying Pencil", around 1,700 were built, originally for carrying passengers.
Collecting aircraft is a small yet burgeoning market for collectors and investors. Last year's EAA Airventure auction in Wisconsin saw a number of rare aircraft go under the hammer, including a Socata TBM 700 for $900,000.
A 1917 Curtiss MF Seagull Flying Boat, which no longer flies, sold for $506,000 at Bonhams in 2010 while the only fully-restored 1929 Hamilton Metalplane H-47 achieved $671,000 at Barrett-Jackson.
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