That way the 16-year-old will have the best excuse for ditching his homework on the return trip.
The year 12 Mount Aspiring College pupil will join the New Zealand swim team at a training camp in Orlando, Florida later this week to help acclimatise and fine-tune preparations.
His mother, Claire McLean, said Hamish was getting very excited.
''It is all go at the moment. He is packing his bags and getting his school work organised to take,'' Claire said.
''He is very excited and training hard.''
Wait on. Back up the mobile library. Homework? Really?
''You can't say that. He is in year 12. It's NCEA.''
The school year has already been quite disrupted. He got the good news he was heading to Rio in May while in a maths class, and last term he went to Spain and Germany to compete and train.
He returned with ''loads of medals'' and ''has had a successful year getting ready for Rio''.
But returning from Brazil with a keepsake might be a tad ambitious. Hamish is targeting the Tokyo Paralympics in four years' time and just hopes to make a final or two at Rio.
''His goal has always been Tokyo and he has just come on leaps and bounds in the last couple of years.
''He qualified for worlds last year and went to Glasgow. That was his first real big experience. He got into the final there in the 400m freestyle, which sort of surprised everybody and put him on the radar.''
McLean will contest the 50m, 100m and 400m freestyle as well as the 200m individual medley. The latter two are his best events.
His campaign gets under way on September 10 with the 50m freestyle. The 200m individual medley starts on September 12. The following day, he races in the 400m freestyle and later in the week will contest the 100m freestyle.
''He is hoping to represent New Zealand well is probably how I would say it.
''It will be a great experience to travel with the team. He is with really seasoned swimmers like Sophie Pascoe, Cameron Leslie and Mary Fisher. He has amazing coaches in Gary Francis and Jon [Shaw] and a great support team.
''He will be learning how to prepare and swim at his optimum. It will be a huge learning exercise for him.''
McLean's mother and his father, Alastair, will travel to Brazil to support their son.
