One partygoer, who did not want to be named, said similar events had happened in previous years but were not as large as the one on Thursday. He had heard about the party from friends and thought it had been organised by word of mouth.
Organisers ensured safety was paramount but by the end of the party it was difficult to ensure everyone was wearing a lifejacket, he said.
"We all went to the top of the island for photos and a bit of a boogie and when everyone left to go back down to the beach and boats ... we were real focused on leaving no rubbish up there."
Another partygoer, who also did not want to be named, said he was a sober boat pilot and was there helping people back to shore.
"I did a couple of trips to get some people back ... I'd say there were just over 100 people though, not even close to 200."
Queenstown Lakes deputy mayor Calum MacLeod said it was likely there would be an investigation into the party.
"We're not necessarily looking at handing out fines but it's obvious if this or something similar is going to happen again, there needs to be more communication and organisation."
Mcleod visited the island yesterday afternoon and said he was surprised to find most of the left-over rubbish had been cleaned up. The fire also seemed to have been well dealt with, he said.
"You can't really fault them on their clean-up."
However, lake swimmer and the Ruby Swim event organiser Eddie Spearing said he was disappointed to find deflated inflatables along Waterfall Creek Rd and bottles and cans on Ruby Island and in the lake when he went for a swim about 6.30am yesterday.
"The place is a bloody mess ... There's nothing wrong with having a bit of fun but just clean up after yourself."
It was infuriating a group of people could have a party on the island with only the smallest amount of organisation and without council consent, he said.
"With the Ruby Swim we have to jump through so many hoops to get all the consent and that sort of thing and this party that who knows how it was organised or who organised it just goes ahead and does it.
"And in the end no one is responsible."
Queenstown-Lakes district harbourmaster Marty Black said no infringement notices had been issued, or were likely to be, as the priority at the time was to ensure everyone was safe.
"It's a strange one and I don't think I have heard anything like it before and there was the potential for something to go very wrong, so at that moment we wanted to make sure everyone was safe."
Many of those on the water were wearing lifejackets but were also very intoxicated.
"If you're too drunk to put your lifejacket on properly or know what you're doing, the lifejacket isn't much use."
Sergeant Aaron Nicholson, of Wanaka, said police were not investigating the circumstances surrounding the party.
Ruby Island
• Ruby Island reserve (3ha) controlled by QLDC.
• Open to public all year round.
• Year-round fire ban but council-operated gas barbecue available.
• No alcohol or smoking ban.
