Vice:
As the crisis wore on, the Canadian government negotiated the exchange of crews from the ships. Supplies came in from Egypt, some sailors went home and others stayed on, but Egypt would not allow the ships to leave the canal.
Over the next eight years, a weird system developed.
...
ships were stranded in the Great Bitter Lake, a salt lake connected to the canal. Unable to leave, the crews, dubbed the "Yellow Fleet" because of the desert sand that eventually covered them, developed their own society at sea. This society developed its own postal service and stamps, and held a version of the Olympics in 1968.