Letcher began rowing aged 13 at
Radford College in the
ACT and his senior rowing has been from the Black Mountain Rowing Club, Canberra. He won a junior national title in a schoolboy coxed quad at the 2011
Australian Rowing Championships. He won the national U19 single and quad scull titles in 2012, while still at school and racing for Radford College, and national U23 titles in all three sculling boat classes at the 2015
Australian Rowing Championships now racing in Australian selection crews in Black Mountain RC colours. From 2014 to 2016 Letcher competed for the
Australian National University Boat Club (where he was studying engineering) at the national university championships winning single and double sculls events in 2015 and 2016. He was the 2016 ANU Sports Star of the Year. Letcher's first state selection for the
Australian Capital Territory was in the 2015 men's eight competing for the King's Cup as well as the single scull for the President's Cup at the National Interstate Regatta. In 2016 and 2017 Letcher was again the ACT representative single sculler at the Interstate regatta. He took the silver medal in 2017. In 2017 Letcher won the Australian quad scull championship rowing in a composite selection crew with
Caleb Antill,
Hamish Playfair and
David Watts. In 2021 he again won an Australian championship title in the open men's quad scull. ==International representative rowing==