"We'll get them standing by the end of the day. Here's hoping it's not too big."
He expected the lesson to be "quite cool", with his partner in The Block, Dylz Junior (Dylan Guitink), joining afterwards to "fix up some sausies".
He said he was looking forward to teaching the auction winners how to surf, because the sport proved therapeutic after having a hard day.
"It just washes everything away. I'm addicted to the feeling of surfing."
The $1000 paid for the lesson would help make up 36 backpacks for Tauranga children in care.
"It gives the kids the bare essentials, books and clothes. For them it means a lot," he said.
Mr Cossey's parents were foster carers which meant he grew up alongside foster children - many would arrive in the early hours of the morning with just a rubbish bag holding their belongings
His family had about 15 to 20 foster children come through their home.
He remembered his mother waking him and his siblings in the middle of the night when a child arrived. They would all have a Milo and chocolate fingers and he would then show them their Lego.
Foster Hope Charitable Trust chairwoman Louise Allnutt said the money raised would go directly to 36 children in the region, who would get a small pack with items such as toothbrush, toothpaste, soap, nappies and a soft toy.
Ms Allnutt said she hoped a person or business in Tauranga could start up a drop-off point, where donors could bring items for the packs.
"We'd love to have Tauranga on board. It's a group we know wants to support us, and has supported us in the past," she said.
Foster children
As of September 2016, there are 194 children under the care of Child, Youth and Family in Tauranga.
