The budding rocket engineers spent six hours last Monday searching for the rocket with a group of volunteers through an area roughly 350 metres by 350 metres.
Mr Buchanan was confident they broke the NZ altitude record, however they couldn't confirm that until they recovered the rocket and analysed the on-board data.
He said the rocket was not overly expensive and was "easily replaceable''.
"Much more time and effort was put into it than money.''
The rocket was owned by the University of Canterbury rocketry group and had survived a handful of other flights before it was lost.
The team were looking at attempting the world altitude record for the class of motor the rocket used "now that we think we at least have the capability of getting the New Zealand one''.
"We're confident that the rocket went higher than the New Zealand altitude record, but we can't officially say that.''