Hi, We are planning a day trip to Lake Como from Milan.mid October. We plan to board from Cadorna to Como lago-ferry to Bellagio - Varenna and return from Varenna to Milan Central since we are staying close to central. If I buy a ticket from Milan Central to board From Varenna back to Milan how do I validate the tickets since there is no ticket office in Varenna? Should I book the tickets in advance online? What happens if the ferries are overcrowded? Would there be another boat at the same time? Any advice would be appreciated. Thank you.