Elliot (61) will be sailing in the same boat he used in the same event in 1968.
He said he would get a great feeling of nostalgia and pride when he sailed in a boat that won six of the seven races and was named best boat at the regatta more than 40 years ago.
"It's going to be a rather special occasion and something I am really looking forward to."
Elliot said the boat was in his family until about 1973 or 1974, when his father had to sell it so his mother, who was sick at the time, could get a colour television.
"We never thought we would ever see it again."
Scamper was bought by Ken Camp, whose own father had built the yacht in 1964.
It was bought back by Elliot's younger brother, Lex, in 2009 after he became aware it was coming up for sale in Christchurch.
Lex Elliot (60), who is also sailing at the national championships, jokingly said he would let his brother sail it, as long as he did not beat him.
Z class squadron commodore Gordon Marr said there were many traditions in sailing, but not many regattas would have had a yacht at the same event after such a long time away.
"It will be a special moment," Marr said.
This year's regatta will have 19 boats competing, eight from the North Island and the remainder from the South.
Defending champions Brent Griffiths (skipper) and Aaron Judd (crew), from the Paremata yacht club in Wellington, are among those competing.
Z class sailing involves dinghy boats with two-man crews. It has been around since 1924, when it was known as the Cornwell Cup. It stopped in 1975 and was resurrected in the early 1980s as the national Z class championships.
Marr said it was one of the oldest sailing regattas in the country.
The Elliots and Marr, who have all sailed for Otago, began competing again last year, for the first time since 1969, when there was an age limit of 19 and younger.
All sailors will be competing in their own boats, unlike in 1968 when competitors drew boat names out of a hat.
The event starts today at the Vauxhall Yacht Club with a sponsors and supporters day, before racing is held tomorrow and on Saturday.
Sunday is a lay day and is also set aside for the national mono type race and a north-south handicap challenge.
