Letcher's senior club rowing has been from the Black MountainRowing Club in Canberra. Letcher first made state selection for the Australian Capital Territory in their 2015 men's eight competing for the King's Cup at the Interstate Regatta. That same year he was also the ACT's representative sculler for the President's Cup at the 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 an Australian national quad scull championship title rowing in a composite selection crew with Caleb Antill, Hamish Playfair and David Watts.
International representative rowing
Letcher made his Australian representative debut in the quad scull at the World Junior Rowing Championships in 2012. They rowed to a sixteenth placing. In 2014 he was selected as Australia's single sculler for the World Rowing U23 Championshipsin Varese where he again finished in sixteenth place. In 2015 he rowed with Thomas Schramko in a double scull at the World Rowing U23 Championships to tenth place. Then in 2016 at the World Rowing U23 Championships in Rotterdam, Letcher rowed in the three seat to an U/23 World Championship gold medal in the quad scull with Schramko, Caleb Antill and Robert Black. In 2017 Letcher was selected in Australia's senior squad and rowed a double scull with David Watts at two World Rowing Cups in Europe and then at the 2017 World Rowing Championships where they finished in overall seventeenth place. In 2018 Letcher rowed in the Australian quad scull at both World Rowing Cups but was a reserve for that crew when they went on to win a silver medal at the 2018 World Rowing Championships. There in Plovdiv Bulgaria, Letcher rowed a single scull in Australian colours finishing in nineteenth place In 2019 Letcher was selected in the Australian senior men's squad for the international representative season. At the WRC II in Poznan he rowed in a double scull with David Bartholot and then at the World Rowing Cup III in Rotterdam he rowed at six in the Australian eight when they finished in sixth place.