The youngster was not sure of how many events he had entered, but the toll on his body was obvious enough.
"It's been a packed weekend - especially yesterday. It was a pretty big day," Mitch said.
"This morning I was falling asleep but then I just had to get myself amped up."
His weekend's work ensured his output at the annual event had surpassed that of older brothers Ross, Scott and Jake, meaning valuable bragging rights were his alone.
"I'll try to let them know, but the older brothers don't like it too much."
Mother Ailsa Cowdrey, whose sons are separated by five years, was proud of all her sons. "It is really good having them so close," Ailsa said. "They've grown up together and they are all mates. The group of boys have all come through together and they're best friends. That's the key in keeping them interested in surf - it's pretty hard with their training schedules and the swimming."
The family had recently moved house, meaning their collective medals were not in their customary position.
"They were up on cork board at our old house, but now they are in shoe boxes. I reckon there are probably about 400-500 medals between us.
"Mitch thinks he's a little bit ripped off because he got some ribbons - back when Ross was competing it was all medals."
Mitch's efforts went some way to addressing that imbalance, but he will likely find life tougher next summer when he moves to the under-16 division.