SUNAPEE, NH (CBS) – Investigators say an “eraser size hole” caused a dinner cruise boat to sink in Sunapee Harbor.

The MV Kearsarge began taking on water around 7:30 p.m. Thursday while it was docked at its winter berth in Sunapee Harbor.

An investigation into the cause revealed an eraser size hole in the coupling from a sea valve to the port engine as the likely cause.

According to the boat owners, the boat also sustained damage to the rudders when it hit the bottom of the harbor. Owners said the boat may need to be taken out of the water for repairs.

The boat was refloated Saturday and is currently in the harbor without external aids.

According to the owners, the boat is expected to be operational in time for the 2013 sailing season.

The MV Kearsarge has been hosting nighttime roast beef dinner buffets and tours of the lake for more than 30 years for tourists and locals.