Crew members showing whānau around double-hulled waka Te Matau a Maui found beer handles strewn about alongside snapped fenders and a broken hand railing.
Lead navigator Piripi Smith said the waka was fortunately fit enough to go on the water as planned for Anzac commemorations this morning.
"We work in with the people from the RSA so that we are there for people to see the waka at 6.30am once they've finished the Anzac memorial."
He said the waka was important to the crew's identity because they didn't want to lose the stories and skills of their tipuna, so they could pass them on to their children.
"Every time we voyage, we are voyaging traditionally, just using the stars, sun and moon to navigate everywhere.
"It's a connection back, to help you get a lot of people understanding the great feats our tipuna have done in terms of the voyaging throughout the Pacific."
He said the waka has been at the Ahuriri inner harbour since 2013 and there had been incidents like this every couple of months.
"What we have issues with is mainly drunk people coming home from the bars, or people under the influence of P and stuff like that come down sometimes during the middle of the day and start jumping on the waka and start abusing crew.
"There is just no getting through to people like this, especially when they are under the influence."
He said they have been working with the Napier City Council to try to get a floating secure berth as part of the Iron Pot development and have also applied to central Government for funding.
In late January the waka was set adrift and damaged by unidentified individuals shortly after its return from a 1500km-plus round trip to the Chatham Islands.
Smith said they have already had half a dozen people working for a day to fix the damage from the most recent incident, and he estimates it will take them two days to fix it completely.
"We're all dedicated to the waka, we all have fulltime jobs, but we all volunteer hours and hours of time."
He said the only solution was more security for the inner harbour to keep the waka away from the public.
"Out of all the waka, there are five voyaging waka in New Zealand, and we are the only ones that anyone can access and just jump on if they want to. Everything else is either in a marina or otherwise secure and away from public access."