Unlike her sister ships, the ROBERT was slated for the role as an anti-aircraft cruiser rather than an LSI. She was taken out of service in January 1943 and Burrard Dry Docks in Vancouver fitted her out. She was armed with ten 4-inch twin HA/LA Mark XXV guns, eight 2-pounder pompoms and twelve Oerlikon 20mm. At the same time, proper director and fire control were added. This was supplemented with some relatively modern Radar, suitable for aircraft warning, surface detection and fire control. The Asdic was also updated and four depth charge throwers added. Now the ROBERT was one of the most powerful A/A ships afloat, for her size.
The ROBERT sailed for England at the end of April, travelling via Panama and Bermuda. The voyage through the canal was made memorable at Colon by the introduction of young Canadian sailors to Central American nightlife...
The ROBERT now joined fast troop convoys to Gibraltar and return as A/A escort. The Bay of Biscay was a relatively dangerous route as the enemy were using long range aircraft as assistance to their U-boats.
By this time the Germans had established very sophisticated radio transmissions both in Spain and France to assist in the location of convoys and to enable the U-boats to home in on them. In addition, the long range Heinkel 177 bomber was able to carry two rocket-assisted flying bombs, which could be targeted by the controlling aircraft from a safe range.
In November 1943, a large Med-UK troop convoy was shadowed by hostile aircraft 250 miles WSW of Cape Vincent, Portugal. A series of U-Boat engagements over a period of four days ensued. Three submarines were destroyed and several damaged during the course of this action with no casualties to the convoy. Among the escorts the Canadian ships CALGARY and SNOWBERRY were credited with sinkings.
Discouraged with the lack of success of their U-Boats, the Germans then adopted new tactics by making strong assaults with large forces of bomber aircraft operating from bases in France. Four-engined FW200s carried out conventional bombing but the surprise threat was from HE-177s equipped with rocket-assisted, radio-controlled, flying bombs. The ROBERT arrived at the height of the action and fired everything she had for the next two and a half-hours.
Despite the ferocity of the attack, the A/A fire saved her from at least one flying bomb and held the casualties of the convoy to one ship with no personnel loss.
This was the first major air attack against Atlantic convoys in over a year and introduced new methods of anti-ship warfare. At a later date, the ATHABASKA was not so lucky under similar circumstances when a flying bomb passed through her before detonating on the other side.