The club was insured, but it was not known if all costs would be covered.
The financially strapped club maintains their gear carefully to avoid costly repairs.
"To have this happen is just devastating," Ms Mason said.
The attack came after a long-running dispute with Maori activists over the ownership of Lake Horowhenua.
Ms Mason said the club had been targeted by threats from the group since 2007.
In the last year, aggression had grown, she said.
"That's probably because our club has grown in the last year and we've been using the lake more, and there's been a lot more activity."
While most of the club's rowers would probably not see much of the season, "our spirit's not broken", Ms Mason said.
Now that daylight saving is underway the young rowers should be starting to prepare three time a week for regattas.
"But now we don't have any boats to use."
Police were investigating the incident, which happened sometime between 8pm Friday and 8am on Saturday.