Final answer:
George Pocock used Cedar wood starting in 1927 to construct racing shells, owing to its lightness and durability.
Step-by-step explanation:
George Pocock was a significant figure in the field of competitive rowing, famed for his craftsmanship in making racing shells. In 1927, he began constructing boats using Cedar, which is renowned for its lightweight and rot-resistant qualities, making it ideal for creating fast and durable racing boats. Pocock's innovative use of Cedar wood significantly influenced the construction of racing shells, setting new standards in the sport.