Liverpool City Council says 800,000 people spent an average of £40 each during the three-day street theatre event featuring giant puppets in April.
The £32m take would be nearly three times the original estimate. Birmingham-based Vector Research produced the figures for the council following the event, which was part of the city's Titanic centenary festivities.
The average spend, Vector says, was £40.74 per person, with those staying overnight spending £34.55 each on accommodation. Nearly £10.5m was spent on accommodation and £20m was on restaurants, bars, shops and other attractions.
Half of the visitors interviewed were from the UK outside Liverpool, with 43% from Liverpool and the remainder from overseas.
Mayor of Liverpool, Cllr Joe Anderson, said: "This was the biggest event in Liverpool's history.
"Liverpool is the only city in the country that can deliver such a giant cultural event, which has also resulted in giant economic benefits for the city. Sea Odyssey demonstrates how ambitious I want this city to be. We need to think in giant terms – in this case, literally. And thanks to the creative brilliance of Royal de Luxe, the hard work of the city council's culture team and the amazing support of members of the public we have put on a spectacular show which captured people's hearts and imagination.
"I am determined that we will put on more of these types of events in the future to further enhance our reputation as a capital of culture."
Separate figures published by Liverpool City Council show Saturday 21 April, during the Sea Odyssey weekend, was the busiest retail day of the year. Also on the Saturday there was 99% hotel occupancy in the city and Liverpool One sales were up 25% on the equivalent day last year. Footfall recorded by National Museums Liverpool showed 100% increase.
During the three days in April the city came to a standstill as crowds joined together to witness the journey of three giants as they travelled across the city. The event delivered international media coverage in the LA Times, Le Monde, India Times, Vancouver Sun and the San Francisco Chronicle. More than 200 items appeared in the media, giving an equivalent advertising value of around £11m.
- Place has uploaded a full version of the research report for public view in Google Documents here