I have heard tell that Kara's (or Hummers) were commercially manufactured out of aluminum many years ago, but I've never confirmed this. The friend referred to in the website face page is the father of the esteemed waterfowl biologist (now with DU) Dale Humberg.
Anyway, the old man passed on his passion to Dale who migrated south to Missouri's (world-class) wildlife resource agency - Mo Department of Conservation.

The design has been refined by many, and plans are readily available, as the website indicates.
I don't know of anything exactly like the KARA ever being commercially built from aluminum, but this boat known as the Bustle was manufactured from galvanized sheet metal around 1905. They never went into the commercial building due to all the coast guard requirements for testing and such.

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