From 1971 to 1972 he was acting president and he took the chair in 1972-1973.
In March of 1975 the club, under Eric Bloomfield, hosted the biggest Rotary conference held in New Zealand up to that time, with 800 registrations received four months before the conference.
"At that time there were only 550 beds in Masterton," he said.
"We put them up in accommodation in Carterton, in caravans and in members' homes."
Organiser Rex Tatton, now 93 and the only other 50-year member, greeted every visitor with a bottle of beer and a can of fizz.
Feeding the multitudes was a massive job
The organisers were litter-conscious too. There was much debate about boxed lunches for a meal to be had in Queen Elizabeth Park, and rather than risk creating litter they peeled 800 boiled eggs for the delegates.
"That was a huge success and marked a turning point for district conferences," he said.
Jim Wagg paid tribute to Dr Dennison, who with his friend and fellow medical man Owen Prior joined Rotary 30 years ago. Dr Dennison served on many Rotary committees.
After he retired he became very involved in birdlife and, later, the Henley Men's Shed. In 2007 he became a Member of the Order of New Zealand.
"He is a very keen vegetable gardener and a better-than-average cook, helping out at the Henley Men's Shed. He is a very keen and excellent woodworker, noted in particular for his walking sticks."
Dr Dennison received his Paul Harris Fellowship in 1987 and Eric in 1995.
Both men spoke fondly of their time in Rotary. Dr Dennison referred in particular to the "Tonga team", in which a team from Masterton spent 10 days building a hall at a college in the island state.
"Doing good and having fun as well" summed up his experience of Rotary.
District Governor Anthony Scott, from Wellington, said Rotary was a marvellous organisation because of men like Tenick Dennison and Eric Bloomfield. He presented both with certificates.