Half Distance 70.3 Triathlon Lahti, Finland: Course Overview Swim Course: Lake Vesijärvi (1.9 km / 1.2 miles) Experience the pristine waters of Lake Vesijärvi with a one-loop swim course located near the iconic Sibelius Hall. The swim start, exit, and finish are all conveniently situated at Satamakatu, making transitions seamless. Expect an average water temperature of 64°F (18°C). Bike Course: Scenic Finnish Countryside (90 km / 56 miles) The 90 km bike course takes you through the ...