A large vegetation fire burning above Lake Wakatipu has grown beyond 146 hectares, with firefighters continuing efforts to contain three active areas at Walter Peak.

Fire and Emergency Assistant District Commander Nic McQuillan said about 25 firefighters and incident management staff were involved in the operation, supported by six helicopters.

The fire remains uncontained, but crews have successfully protected the Walter Peak homestead and nearby buildings.

Firefighters from Queenstown, Frankton, Glenorchy and Mossburn are working on the western flank to strengthen the perimeter, while helicopters continue attacking the fire from the air.

Operations will continue until sunset before being suspended overnight. Firefighters and aircraft are expected to resume work on Wednesday morning.

McQuillan said people should expect to see signs of fire overnight and into Wednesday.

Boat operators and people using private watercraft are being asked to stay well away from the Walter Peak Station shoreline while helicopters fill monsoon buckets from the lake.

The fire is continuing to move quickly downwind and is burning through pockets of vegetation, causing periods of heavier smoke.

Smoke is expected to continue drifting across Lake Wakatipu towards Jacks Point and Hanleys Farm.

People affected by the smoke are being advised to keep doors and windows closed to reduce exposure.

At 3pm, the fire had been mapped at 146 hectares with a perimeter of almost 6 kilometres.

McQuillan said the fire had grown further since then.