When war broke out in September 1939, the Royal Canadian Navy had in commission only six destroyers, four minesweepers, the motor vessel SKIDEGATE, and the training schooner VENTURE, and the great and immediate need was for large numbers of small vessels for coastal patrol, the examination and control of merchant shipping, harbour service, and a variety of similar tasks.  Many of these small vessels were purchased or requisitioned from various Government Departments and from private owners, but a few were acquired as free gifts from patriotic citizens.  HMCS AMBLER was one of the vessels acquired in this way, when her owner, Mr. C. H. Sheppard of Waubashene, Ontario, turned her over to the RCN at Midland, Ontario, early in May 1940.

The steel, diesel-drive yacht AMBLER was a fairly old vessel which had been built in New York in 1922 to the following specifications:

                        Length at water-line:                       122’  8.5”

                        Breadth, extreme:                            22’  8.5”

                        Draught, forward:                             7’

                        Draught, aft:                                     9’  11.6”

                        Tonnage, gross:                               264.11 tons

                        Machinery:                                       2 Winston Diesels of 200 horse-power each

                        Speed, maximum:                           10.5 knots

                        Speed, economical:                         8.5 knots.

When fitted out for service by the RCN her armament consisted of light weapons (1 Vickers light machine-gun, 2 stripped Lewis guns, and miscellaneous small arms), but she did carry four depth-charges aft.  These depth-charges were more in the nature of a deterrent than anything else, for AMBLER had no asdics with which to locate a submerged U-boat.

HMCS AMBLER joined the RCN on 6 May 1940 when she was taken over by a detachment from HMCS STADACONA headed by A/Lieutenant R. S. Kelley, RCNR.  Lieutenant Kelley apparently commissioned the ship on that day, but instead of hoisting the White Ensign, as is customary, he hoisted the Blue, and under this ensign the vessel sailed from Midland to Montreal, where she arrived on 14 May 1940.  This departure from precedent was made on orders from Naval Headquarters in deference to the Rush-Bagot Agreement of 1817 limiting the number of armed warships on the Great Lakes.

AMBLER did not remain long at Montreal but continued down the river, this time under the White Ensign, and arrived at Quebec on 17 May.  Quebec was the headquarters of the St. Lawrence Patrol, the force to which AMBLER had been allocated, and there she was refitted and armed in preparation for her river patrol duties.  In less than six weeks she was ready, and on 26 June she sailed on her first operational mission, a survey and patrol of the river as far down as Murray Bay on the North Shore.

During the remainder of the navigational season of 1940, HMCS AMBLER operated with the St. Lawrence Patrol, usually as Senior Officer’s ship, patrolling the river from Isle aux Coudres to the western tip of Anticosti Island.  When ice closed the river in the autumn, AMBLER was laid up at Quebec, and during the winter, she was overhauled and refitted to be ready for operations in the spring.

On 14 May 1941, she recommissioned and began another season of patrolling in the river.  It was uneventful work, for the U-boats were not to penetrate the Gulf and Upper River for another year; but it was seldom dull, for inshore navigation, especially in a river crowded with shipping of all kinds, is never a routine job.  Occasionally, a task that was out of the ordinary had to be carried out, and this helped to relieve the tedium of constant patrolling.  On 4 September 1941, for instance, His Royal Highness the Duke of Kent arrived in Quebec, and AMBLER has honoured by being assigned to land him from his ship.

HMCS AMBLER continued to serve with the St. Lawrence Patrol until the late autumn, when a signal arrived from Ottawa transferring her to Halifax.  She sailed from Quebec on 28 October 1941 and arrived at Halifax on 4 November.  There she became tender to the training establishment HMCS STADACONA and operated out from Halifax as a training ship chiefly for New Entry seaman.  When training at Halifax was removed from the jurisdiction of STADACONA and placed under HMCS CORNWALLIS in May 1942, AMBLER was assigned to the latter and carried on with her former duties.  When CORNWALLIS was transferred from Halifax to a new site near Deep Brook, Nova Scotia, AMBLER transferred also as one of the training ships of the new establishment.  Throughout the remainder of the war, except when undergoing periodic refits or repairs, AMBLER remained with CORNWALLIS as a training ship.

With the end of the war and the cessation of training, AMBLER was declared surplus to naval requirements, and on 20 July 1945, she was transferred to the administration of the Naval Officer in Charge, Sydney, for disposal.  Since AMBLER had been a free gift to the RCN, the former owner was asked whether he wished the vessel returned to him now that the Service no longer required her.  On 2 November 1945, Mr. Sheppard rejected this offer, but a few days later, on 13 November, he reversed his decision and asked that the RCN make out a bill of sale for the vessel in favour of Mr. R. B. Pratt, 166 Brookdale Ave., Toronto.  This was done, but Mr. Pratt did not take delivery.  Apparently, he sold the vessel to Mr. W. N. Macdonald of Sydney, N.S., and on 8 February 1946, AMBLER was handed over to him.  Late in 1947, AMBLER’s Canadian register was closed, the ship having been sold to Greek interests.