Two young tourists using a willow branch to paddle the plastic dinghy they had taken were rescued after being swept into the middle of a lake.

Harbourmaster Marty Black said the couple from Central America had seen the boat when they were at Glendhu Bay at Lake Wanaka late this afternoon and borrowed it to go a short distance offshore to take photographs.

They used a willow branch for a paddle and had no lifejackets or safety gear. They were quickly blown offshore by strong southerly winds.

The pair were rescued by the manager of the Glendhu Bay Motor Camp, who noticed them drifting in the area between Sandspit and Fernburn. He alerted a local worker who happened to have a boat nearby.

Mr Black said it appeared the tourists had been in the dinghy for about 20 minutes when they were rescued and brought back to shore "wet, cold and frightened".

"They were incredibly lucky that they didn't capsize and drown. Even though it sounds like they only meant to go out and take a few pictures, this was a recipe for disaster."