From the Canadian Armed Forces publication Sentinel, Volume 11, Number 3, 1975/3.
Farewell to Rainbow
HMCS Rainbow (SS / 75) steams by Clover Point at Victoria, B.C. in the summer of 1974 during her last sailpast with Maritime Forces Pacific. Canad's only submarine on the west coast was paid off at CFB Esquimalt December 31, 1974.
The "Tench" class submarine was a true veteran, having been first commissioned in January 1945 as the USS Argonaut. She completed one combat patrol in Japanese waters before the end of the Second World War.
The Argonaut served with the U.S. Navy until December 2, 1968, when she was purchased by Canada. On that day she was commissioned as HMCS Rainbow, am since then has served with Maritime Forces Pacific at Esquimalt.
She was primarily a training vessel, developing not only her crew's skills but also the anti-submarine capabilities of the west coast destroyer squadrons and maritime patrol aircraft. An indication of her active career is her record of dives — she passed the ten thousand mark last summer.
The Rainbow's last few months were as unusual as any of her career. Originally scheduled to be paid off on August 1, 1974, during June her service was extended to the end of the year. With many of the boat's crew already assigned to new duties, the captain faced a manning problem.
A call for volunteers went out, and soon the ranks were full of ex-Rainbow crewmen, east coast submariners, and naval reservists. there was even one paratrooper who had never been onboard a submarine before. they all pulled together, and the submarine successfully completed its program.
But there were to be no more extensions for the rainbow. On 31 December the Canadian flag was lowered for the last time.
The Rainbow was a good boat. She will be missed.