Interesting pic! Definitely a Kaman UH-2A (or UH-2B) with single T-58 engine. Of course a test/eval setting and with the H-34 in background would be period correct. The question is "where" and "what"?
Good find.
There was a multi volume "History and Chronicle of Marine Aviation" published late 1970's or early 1980's that I loved to read at the NAS Pensacola base library that was a detailed technical and operationalo reference if every USMC air program - multi volume set by decade with amazing "color plates", data tables, program documents, etc. I bet this lone Seasprite is documented in there. It contains fascinating info on H-46 46 and H-53 program development and key insights into design decisions especially around avionics.
I have yet to locate a digital version - it was published by HQMC.