One of those is Southern Alps Air, based at Wanaka Airport, which took delivery of a GA8 Airvan from Australia on Tuesday.
Owners Anne and Paul Cooper bought the plane to keep up with passenger demand, specifically on the Wanaka to Milford Sound route.
"Over the past year we have really seen the number of tourists wanting to get over to Milford Sound really shoot up and we think it’s going to get busier," Mr Cooper said.
Two more planes were planned for sometime in the next five years, which would add to the fleet of six the company already had.
Able to carry seven passengers, the second-hand plane cost close to $500,000, but the couple were confident their investment would pay off, Mr Cooper said.
In operation since 1972, the airline flew mostly out of Wanaka Airport but also from Makarora, Mr Cooper said.
At peak times the airline could make six or seven return trips to Milford Sound, he said.
Lake Wanaka Tourism general manager James Helmore said many tourism operators were upgrading in an effort to meet the needs of an increasing number of visitors.
New businesses were able to start with confidence in the market and older ones were upgrading in the knowledge they were making a solid investment, he said.
For businesses such as Southern Alps Air, which has been based in Wanaka for more than 30 years, the strengthening of the tourism market was reward for much hard work when the outlook might not have been so positive, Mr Helmore said.
According to the Commercial Accommodation Monitor, Wanaka recorded almost 795,000 bed nights in the year ending July, a record number, Mr Helmore said.
"It’s quite a change from a few years ago, when things weren’t so certain."