At yesterday's hospital advisory committee meeting, he said travel was becoming "more and more" of an issue as more staff moved between Dunedin and Invercargill.
It concerned him there were some very expensive staff spending long periods in cars, which was not good use of their time.
All options needed to be explored "up to and including whether we should have a helicopter going down there".
Board chief operating officer Vivian Blake said the board hired a four-seater aeroplane at a cost of $1300 return for travel to Invercargill on Tuesdays.
She said travelling by car not only involved a lot of unproductive time; it was also very tiring.
"It can't be good for you."
Committee member Dame Norma Restieaux said there were also safety issues when people were driving such long distances in a day.
Chief medical officer Richard Bunton said doing a clinic in Invercargill involved a long day, although he commented some senior staff might not be thankful for the prospect of getting on a helicopter in a "rip-roaring southerly" to go to Invercargill.
He said he appreciated that it was much better to shift a doctor to see 30 patients than vice versa.
Mr Thomson said the board needed to know what the cost of the various options were because the situation was "only going to get worse".
Concern was also expressed at the meeting about the cancellation of the Mainland Air thrice-weekly passenger service between Dunedin and Invercargill this month after six weeks.
This affected the one service the boards have in common, the Southern Blood and Cancer Service.
The emergency medicine and surgery services group report to the committee referred to receiving one day's notice of the cancellation.
"Given the amount of outpatient clinic rescheduling and anticipated use of the service for further collaborative service delivery across the region, this is a major concern for both district health boards," the report said.
While the two health boards have only one service in common, there is increasing collaboration between the boards involving clinicians and senior management staff.
The report also referred to transport difficulties hampering progress towards a monthly endocrinology clinic being provided in Southland by Otago clinicians.
