The Warrnambool Swimming Club mentor takes care of beginners, which William McPhee, Kirra Umbers, Laura Vallence and Meg Flaherty were four years ago.

"I've had them since they were about eight years old," he said.

"They started off just doing one session a week, then they moved to two to three to four sessions."

Their progression has helped them get to where they are now ? prepared to contest the Victorian 12 and under swimming championships at Melbourne Sports and Aquatic Centre.

This weekend's event will welcome almost 500 competitors ? including overseas swimmers ? from 80 clubs.

While Laura contested the titles last year, Meg, William and Kirra will make their debut.

"There's probably five or six more that qualified but they just had one event so they didn't want to go all that way for one event," Sobey said.

Heats are held in the morning, with the 10 fastest swimmers progressing to the finals in the evening.

Meg will compete in the 11 and under girls' 100-metre breaststroke and butterfly, while Laura has entered the 12 and under girls' 100m breaststroke.

William is in the 12 and under boys' 100m freestyle and butterfly and the 200m individual medley. Kirra will hit the pool for the 11 and under girls' 100m backstroke, freestyle and butterfly and the 200m individual medley.

"I think they all should swim personal best times and if they finished in the top 30 that would be great," Sobey said.

"Just getting there is a fair effort."

Sobey said he loved teaching the younger children, who would soon move on to further their development with the club's head coach Jayson Lamb.