This is the cool one, the uber mack daddy document of the thrust vectored sport. NACA Research Memorandum, RM L52D10, “Preliminary Experimental Investigation of the Flight of a Person Supported by a Jet Thrust Device Attached to His Feet”. Detailing Charley Zimmerman’s experiments with hooking up a firehose to a plywood board and kicking off (albiet slowly) the sport of vectored thrust flight.
Here is the first announcement in a publication to the world after it’s top secret classification was removed. As the record shows, the “apparatus” was first tested on February 2, 1951, the Research Memorandum published two years later on January 15, 1953, then stamped as “Classified” and then made public in 1955.
Link for full PDF document RM L52D10 here.
Here is one of the best images showing the classic board steering definitions.
Page 25 Showing the “test subject” doing a nice kinesthetic correction on the “board”