Georgia secured their spot by virtue of an impressive 22-9 win over Romania in March. About 30,000 fans packed into the Mikheil Meskhi Stadium in Tbilisi to see the "Lelos" secure their place.
"It was an amazing feeling for everyone involved, especially as the qualification process was over two years and both teams were undefeated going into the game," Haig told the Chronicle.
He said it was also made special because it was a moment he shared with his wife Angelique and daughters Molly and Milly.
"Ang and the girls came down on to the ground after the game and did the lap of honour with the team in front of the fans. It was amazing."
He said he regarded the occasion as one of the finest in his long association with rugby .
"I've had other great moments with other teams I've coached but this was special because of the length of time it took and the way we progressed as a team over that time.
"Qualifying for your first ever RWC has to be one of those memories that will be right up there after I retire."
Haig said Georgia was "rugby mad" but this win added new interest in the sport.
"It's also generated massive support from all areas of the country in general as well as the Government, which is so important to us for continued funding.
"Players have been in big demand from the media for interviews, not only here in Georgia but from all over Europe."
The team had a test window next month but the aim was to build as much depth as possible in each position, Haig said. That would mean giving some new players an opportunity over the next 12 months to prove to the selectors they were worthy of making the RWC squad.
For the players as well as Haig's coaching team, moving into the northern hemisphere summer doesn't mean the pressure has come off.
"All the national players are monitored closely, whether they play in France or here in Georgia. They have a 'periodised programme' that involves every aspect of their strength and conditioning and skills training.
"That programme is valid right through to the tournament so that we get to the RWC in the very best condition," Haig said.
In terms of strategy before the tournament, he said the team would go to the UK the best-prepared Georgian team to date.
"We already have our bases chosen for the tournament and we will go to England two weeks earlier than the official start date so that we can play three pre-tournament warm-up matches against two English premiership sides and one international team.
"We've planned a large amount of our 2015 programme already and so we are well ahead with our preparations."
Looking beyond next year, Haig said decisions would have to made and that would involve family as a priority.
"My contract ends in December next year," he said.
"Certainly a contract extension is possible and definitely something I would consider as I enjoy the role very much.
"However, before making any decision, it would be something that we would discuss as a family and the outcome would be based on what was best for all of us. With our eldest daughter [Molly] nearly at high-school age, that's something we have to consider," Haig said.
