The newest passenger boat for Maine's Casco Bay Lines will be running a diesel-electric hybrid propulsion engine. The hybrid will be handling the Portland to Peaks Island run, fully on electricity. The diesel engine will function as a backup, or be engaged for trips longer than the normal run. This assigned route is approximately 2.5 miles, which should allow the ferry to travel one way, charge at docking (~10-15 minutes) and run the return trip on electricity as well.