Tampa Bay was resting on our test day, with perfect weather, including mild temperatures and a gentle breeze. With Yamaha's relatively new Saltwater Series II-SDS 15-by-21-inch props, the pair of 300s lifted the Jupiter 30 onto plane in 4.5 seconds and hit 30 mph in 8.5 seconds. Top speed was 56.5 mph at 5,700 rpm while consuming 52.7 gph for an economy of 1.07 mpg. Cruising at a seemingly snail's pace of 34.7 mph turning 3,500 rpm sipped a conservative 19.4 gph (1.79 mpg). Trolling speed of around 8 mph affords 1.82 mpg while using a mere 4.5 gph. To put these speeds into perspective, note that the weight listed in this boat's specifications is dry with just the engines. Adding fuel, two people aboard and equipment, etc., brought our test weight to around 10,000 pounds.