Dublin's Tall Ships festival generated spending of nearly €30m compared to a cost of just over €3m, according to a report.
The report for Dublin City Council found that a total of 1.25m people attended the four-day event in August, with most being from Dublin, but 27% were from the rest of Ireland and 12% from overseas.
Visitors from outside the capital generated 50,000 bed nights valued at over €2m, according to an independent assessment by Sheffield Haslam University.
The council report found that anti-social behaviour and medical emergencies were insignificant, but delays and access problems were experienced on the first day.
The international organisers, Self Training International, said they would welcome a bid from Dublin to host the event again in 2016.
However, because of 1916 Centenary celebrations that year and budgetary constraints the report recommends that a bid be delayed until 2018.