The tribunal's decision, which did not name Sands, noted the police summary of facts on his offending.
Police said Sands had been at the Queen Elizabeth II Park pool at the same time as about 50 schoolchildren on the afternoon of December 6, 2010.
He was wearing a rubber flotation tube when he entered the pool's lazy river, which allows swimmers to float in a gentle current.
Sands passed three girls, aged 13 to 15, and reached out to deliberately stroke their thighs.
He did this to two victims twice - one of whom informed a life guard and a teacher.
When spoken to by police, Sands denied the touching had been deliberate, saying it had been a busy day at the pool and there had been a lot of bumping into people.
He later pleaded guilty to the charges and voluntarily stopped teaching pending the tribunal's decision.
Teachers Council's complaints assessment committee lawyer Stefan Kaminski said the offending was at the lower end of the scale, but any offending of its nature by a teacher needed to be treated very seriously.
Sands, representing himself, wrote a "somewhat sarcastic" letter about his frustration with the process, but accepted cancellation of his registration was appropriate.
The tribunal accepted the case was not one of serious sexual assault, but said any teacher convicted of sexual assault must expect to be prevented from teaching in New Zealand schools.
It noted Sands had been seeking appropriate help and did not intend to return to teaching.