In October last year, they returned to the remote Fishermans Bay and installed some waratahs and anchors.
Then in May, the highline was erected and the fun began.
Even though Youmndingouetmoun himself was too afraid to use the highline, he said it "was amazing to watch the others".
"The whole weekend was really amazing just seeing them and being a part of the process from the beginning.
"It was such a great feeling because most of the group came down from Queenstown and Wanaka. So they came up just for the weekend, to see how dedicated and committed they are to their passion is really exciting."
Youmndingouetmoun said taking video for his YouTube channel YoumiTrip is his passion.
"I love to do drone videos so I like to hang out with this group because they always go to spots with a lot of exposure and really dramatic sceneries so it's always cool for me to follow them.
"For this particular project, I was the person who knew the owners so was in charge of organising and logistically talking to the owners."
A kids' slackline festival is being held this Saturday in Christchurch at 181 Hereford St, next to Hammock Forest. Find out more here.