March, April, and May were consumed by drawing and preparing operational equipment, ammunition, and stores, and turning in or discarding equipment that would not be used in France. During this period A and B squadrons received 38 of the M4A4 Sherman V Duplex Drive tanks. C squadron and Regimental Headquarters took on 18 M4A2 Sherman III tanks. The recce troop traded in their Bren Carriers for 11 new American M3A3 Stuart V light tanks. Fully armoured, and armed with a 37mm cannon these were a welcomed improvement but, once again intensive effort on the part of the crews was required to become proficient on their new mounts in the short time remaining before the invasion. The Intercommunication troop received 9 Scout cars and the Anti-Aircraft troop received its final allotment of 6 Crusader III anti-aircraft tanks. In addition, the Regiment also received a small number of another British secret weapon. This was the M4A4 Sherman Vc Firefly. Mounting a highly effective, high velocity, 17 pounder gun, it was the only allied tank that could reliably defeat the heavy German armour encountered in Normandy at normal combat ranges. Initially the Regiment received only 5 of these vehicles and all were assigned to C squadron however two more were received just before embarkation for a special mission which will be discussed later. Once again, the gunners were given only one very brief opportunity to fire a few familiarization rounds from this new weapon before they were put into storage for the invasion.
Unfortunately, as the new vehicles arrived, it was found that many were in less-than-optimal condition, and many were issued without necessary tools. Each new vehicle that arrived had to be de-kitted, fully inspected, overhauled, modified, waterproofed, and re-stowed. For anyone that has never done this, it entails a tremendous amount of work. It was only as a result of the Trojan efforts by the unit fitters, and members of #54 Light Aid Detachment, in conjunction with the whole crew often working long into the night, that the Regiment was ready for D-Day. Following this work each vehicle was then run in for 500 miles, checked again and laid up in preparation for the invasion. In addition to new equipment the Regiment received a large influx of new soldiers, and additional time and much effort was needed to quickly integrate them into the squadrons and update their training as most of them had not yet had the opportunity to work on operational equipment. All personnel also received detailed training in the use of new codes and reading French Maps.
That spring also found the Regiment participating in a series of increasingly complex invasion rehearsals culminating in “Exercise Fabius III” in May. March 5-12 found the entire Regiment involved in a major combined arms exercise PRANK with the 7th Infantry brigade at Studland Bay. This was followed on April 9-12 by Exercise Trousers at Slapton Downs where the DD squadrons were able to utilize some of the Sherman Duplex Drive tanks for the first time. These were still very rare vehicles as full-scale production had only started the previous month. However, the landing tables for this exercise indicate that the DD squadrons were equipped with 26 Sherman Vs (as noted previously, this was the version that the DDs were converted from) and ten Valentines, which were in use as training DDs. The last exercise was Fabius III, which took place in Bracklesham Bay, south of Chichester on the 3rd of May, 1944. This was the final full scale dress rehearsal by the 3rd Division for D-Day. As a matter of security, the Duplex Drive tanks were returned to their waiting LCTs as soon as they had landed and covered with camouflage nets.
As some small compensation for all of their hard work, the Regiment rented the nearby and very popular “Bournemouth Baths” for two days, and the entire regiment enjoyed the luxury of a huge indoor swimming pool, private baths, Turkish baths, and a sunbathing solarium with sun ray lamp equipment.