Authorities in Solomon Islands say it's lucky no one died when a ferry carrying nearly 400 people sank.

The Francis Gerena left Honiara on Friday afternoon carrying 389 people and was heading for North Malaita.

Disaster officials say it went down off the Florida Islands, north of the capital.

The director of the disaster management office, Loti Yates, told Pacific Beat the ferry was overloaded and had been order not to leave port.

"For me I think it was a total lack of common sense from the people who actually took the boat out when they were ordered not to," he said.

Mr Yates said it's extremely lucky there were no casualties.

"People were assuming that once the order was given, people would take heed," he said.

"You know unfortunately not every human being exists on earth would be as obedient as everybody.

"Some would have their own way of doing things and in this case this fella just took the boat and took off."