Not for the easily distracted. Inboard Endurance races are the ultimate test of longevity and proper engine tuning. These races can last from 15 minutes to as long as an hour and tend to top more than 100 miles. Inboard Endurance races have been known to even last as long as 500 miles. Even though they consistently top 100 mph, speed isn’t the only factor for these finely tuned pieces of machinery. The drivers must be in top shape to last the grueling races with rigs built to last. When most boats are back on the beach sitting on trailers, these Chevy big block propelled crafts are just getting started.