To 17 ports; the busiest crossings are to North Greenwich (20 minutes, 29 times a day), Battersea Power Station (1 hour 35 minutes, 29 times a day), Greenwich (30 minutes, 27 times a day), Surrey Quays (40 minutes, 27 times a day), Canary Wharf (44 minutes, 27 times a day), Masthouse Terrace (35 minutes, 26 times a day), Tower of London (56 minutes, 25 times a day) and London Bridge (an hour, 25 times a day).