McLean, a pupil at Mt Aspiring College, dominated the men's AWD events at the Otago championships.
He set an open men's S6 classification record in the 50m breaststroke with his time of 57.66sec.
He also collected five national junior (under-19) records in the 50m butterfly (46.76sec), 100m butterfly (1min 46.28sec), 50m freestyle (39.56sec), 100m breaststroke (2min 1.67sec) and 200m individual medley (3min 44.07sec).
''I'm pleased with the records and proud to represent the Wanaka Swimming Club in Dunedin,'' McLean said.
McLean, who turns 14 tomorrow, was born with dwarfism, a disorder that stops his arms and legs from growing.
The medical name is achondroplasia. Jacquie Ruth, who broke five New Zealand S6 AWD records at the championships, also has the condition.
McLean spent the first two years of his life in a body brace and has been swimming competitively for the past two years, under the direction of Wanaka coaches Fiona Hezinger and Merryn Johnston.
He will have his first taste of international swimming next month, as a member of the New Zealand Paralympic team that will compete at the New South Wales championships in Sydney.
''Hamish wants to represent New Zealand at Commonwealth Games and the Paralympics,'' his mother, Claire McLean, said.
''Hamish puts a lot of effort into his swimming and has five training sessions each week in the pool. He gets great support from the other swimmers in the squad who give him the motivation and inspiration.
''He gets stuck in and does everything he can and participates in all activities at school. He goes skiing at Cardrona in winter and just loves it.''
