Cruise passenger traffic at Piraeus Port increased 29.69 percent in the first five months of 2011, relative to the same period in 2010, the port authority announced on Friday. This increase was 15 percent higher than that forecast at the beginning of the year. There was a total of 567,085 arrivals-departures in 2011, up from 437,274 arrivals-departures in 2010 for the same period.