But critics are looking forward to her set, and organiser Emily Eavis is "super excited" to have SZA on the bill.
"We're delighted that she's in the condition that she is," he added.The first pre-dawn sailing out of Troon took place in challenging conditions with winds gusting at 40mph.
Passengers clutched onto handrails when moving about the ship, a few passengers felt a little queasy - and for those with stronger stomachs, the breakfast trays slipped precariously about on the tables.But despite the choppy conditions, the verdict of passengers was overwhelmingly positive."It has the feel of a cruise ship," said Kenny Browne as he shared a champagne breakfast with his wife Nicky.
"Everyone's waited so long for the ship, so we just wanted to be here to celebrate."Elsewhere a group of construction workers on their way to Arran for a team building day toasted the ship's arrival with cans of lager and were singing by the time it berthed in Brodick.
Mr Mackison said Glen Sannox would make big difference to islanders because it was capable of sailing in more challenging conditions.
"This new generation of ships are more powerful and have more sophisticated thrusters which enables them to get along under more challenging conditions and stronger winds," he explained.Sister Carr, 50, said: "It's highs and lows and aches and pains, but on the whole it is absolutely amazing."
Talking from Corbeny, in France, she said lots of people had been helping along the way, and "feeding me up"."The feet are a little bit sorer than I thought they would be - I have had to go through about three packs of plasters.
"At the beginning I thought 'am I really going to be able to do this?' But, it's manageable," she said.Sister Carr said she had been staying in homes, monasteries or parish centres, and "meeting all sorts of people".