Invited by former Olympic sailor Alberto Sonino, Dick and Jem travel to Venice, Italy, to help save one of the world’s most beautiful cities from the damaging effect of boat pollution. With 40,000 boats commuting around Venice, exhaust from Europe’s largest car-free zone mixes with water and creates an acid that is eroding away the historic buildings’ precious facades. With a stunning U.S. $30,000 boat provided by Alberto, Dick and Jem get to work on creating an electric-powered motor. To power the engine using a clean power resource, Dick and Jem outfit the water taxi with solar panels that re-charge the motor’s batteries. To test the design, Alberto creates a marathon course that will take at least two hours, encountering open water, bridges, tight canals, traffic and a meeting with the head of Venice’s waterways. Satisfied with the result, Dick and Jem next challenge themselves to build an electric speed boat, using a specialized go-kart motor. Will this boat sink or swim?