|Credit: The Last Battle of the Destroyer 'Eilat', between p. 160 & 161.|
To add to the 'chess in the IDF' file, an example from chess in the Israeli navy (in Israel, the navy and air force are part of the IDF as a whole, not independent armed forces). Here is an interesting example from the book The Last Battle of the Destroyer 'Eilat' [הקרב האחרון של המשחתת אילת].
The INS Eilat was an Israeli destroyer sunk by Egypt in Oct. 1967, shortly after the Six Days' War. The last commander of the ship, Commander [Sgan Aluf] Itzhak Shoshan, wrote a book about the event and the ship in general.
In one of the photos in the book, dated 'winter 1966-1967', we see behind Shoshan, again using naval ranks, 'Lieutenant [seren] Mashiach and Lt.-commander [rav seren] Ginzburg playing chess'.
P.S. it seems that the other three officers are playing an informal game of roulette!