Mr Crosbie, who spoke to the Bay of Plenty Times afterwards, said Caitlin had many friends and the high attendance numbers reflected she was loved by a lot of people.
"It was a lovely tribute to Caitlin," he said.
"It reflected what we are as a college and what Caitlin was like as a person and I think the two came together in a wonderful celebration of her life."
The service was very family-orientated and family members shared special memories of theirs, Mr Crosbie said.
Caitlin's brother and sister spoke at the funeral and read tributes on behalf of Calvine O'Minde from Ark Quest College and from teachers Philip Russell and Gemma Tong, who remain in Africa.
Caitlin's long-term friend Lydia Hollister-Jones performed an original song she had written. Mr Crosbie said the song paid tribute to Caitlin and encouraged people to have faith and hope and live a life that reflected that.
The service was co-ordinated and led by pastor Craig Vernall of the Bethlehem Baptist Church.
"The message he gave to the young people was to remember Caitlin by modelling their lives on how she lived hers. To reflect her zest for Jesus and her commitment to making a difference to others rather than by having a picture on a dressing table," Mr Crosbie said.
After the funeral came to a close, mourners lined the college driveway for a guard of honour as the hearse carrying Caitlin's body left the college grounds.
"She was a very special girl," Mr Crosbie said.
Caitlin was one of four people who were killed in a mini-van accident in Kenya last week. Bethlehem College parents Brian and Grace Johnston and Kenyan minivan driver Christopher Mmata also died in the accident.
They were part of a 19-person team from Bethlehem College that was on a volunteer mission to the Ark Quest School in Mahanga.