This cover is franked with an 5-cent U.S. Flag stamp of the era, Scott # 1208; and postmarked January 17, 1966 at Groton, Connecticut.  It has no backstamp(s) or markings; just cancellation machine traces.  The protocol card noting that it was Admiral Rickover's wish that this memento be given to Mr. Hewitt is enclosed.

The USS Narwhal (the third U.S. Navy submarine to bear this name) was completed and launched on 9 September, formally commissioned on served 12 July 1969;  and served with distinction for many years.  While many of her missions were not specified, she served primarily in the Artic countering the threat posed by Soviet Russia.  She was officially decommissioned and stricken from the Navy rolls on 1 July 1999; but was not fully dismantled until 2020.

The addressee, M.W. Hewitt (1932-2015) was a 1957 graduate from the U.S. Naval Academy who had a distinguished career in submarines and then, as he increased in seniority, in complex system and engineer planning for the Navy as a whole.

I offer this cover with no minimum, no reserve.  I do not level handling or packing charges:  your bid and the price of a first-class stamp (.68 in USA, $1.55 everywhere else) will get it to you.  Also, I accept returns for any reason--and if the reason is a material error on my part I will return your postage costs both ways as well.

I was an Army guy; not Navy; but ultimately the same team, eh?  I wound up with several of these interesting covers, and it is a pleasure to offer this one to the eBay world!