"It seems Lake Coleridge has made a claim that we just have to accept," mother Barb Duncan said.
Rob Duncan said he was a wonderful son who rarely caused problems.
"It was probably mum and dad that caused problems for him," he said.
Lindisfarne School Chaplain Rev Warren Fortune said Hamish was low profile "and yet was always very outstanding, quietly getting on with it".
"A steady-as-she-goes approach, where little appeared to fluster him or create unnecessary anxiety."
He died while "grabbing life with both hands".
"Here we have a life, full of promise, nipped in the bud," he said. Teacher Karl Jones made the same move as Hamish in 2010, from Hastings Boys' High School to Lindisfarne College, becoming his Year 11 science teacher. Hamish's familiar face was a comfort in the new environment, where he was very popular for his willingness to tutor fellow students, he said.
After a stirring Lindisfarne student haka, younger brother William spoke fondly of Hamish's dogged determination pursuing his collecting habit and fun times on family holidays.
They attended St John first aid classes, which helped spark Hamish's goal to become an army medic. He was a trainee at the combined-forces Defence Health School at Burnham Military Camp when he died.
Chief instructor, Major Ian Barrett, said he settled into his training easily and was a well-liked, diligent, quiet and unassuming student. Classmate Sarah Coote said he was a remarkable man with an ever-ready grin.
"He was somewhat aloof, strong, capable, compassionate, genuine and had empathetic understanding," she said.
"Along with so many others here, I am so deeply honoured to say I had the chance to know and honour you, to call you a brother, to consider you family."
Remembering his loyalty and achievements would be important for those left behind, Rev Fortune said.
