A quarter century ago Tammy McGillivray served as a lifeguard teaching Paulo Diaz how to swim.

On Saturday McGillivray served as a lifeguard again ... by delivering the West Mountain father's baby daughter.

McGillivray, in her 11th year as a Hamilton police officer, was on patrol at the Linc and Upper James Street when she responded to an ambulance assist call at 11:26 a.m.

"When I got there I ran in with my gloves on and she was ready to deliver," McGillivray said upon finding a 38-week pregnant Helga Diaz in the hall of the couple's second floor.

Joined by colleagues Jack Vanderpol and Tara Copeland, McGillivray recalled her own childbirth experiences -- her children are 17, 15 and 13 -- and prepared to serve and protect.

"I knew things were going to go quick. As soon as she started to crown we knew things were going to happen real fast. We didn't have time to wait for the ambulance."

Mom was exhausted and couldn't push any more. The constable issued a summons of her own.

"You don't have a choice because baby's mouth needs to be exposed. I said 'You gotta push, c'mon' and sure enough another push and I assisted the baby out."

McGillivray, 43, was still on cloud nine as she visited the proud parents and her latest collar ... all five pounds and 11 ounces of her. Released to her parents' loving custody is one Julia Gabriella Diaz.

"For all the things we see on this job we don't get to be part of something so spectacular that's just a positive. This is just amazing. It lines right up there with having your own children.

"That's pretty special. I don't think I will ever forget that," the constable said yesterday during a visit to the McMaster University Children's Hospital.

Paulo said Helga's due date was Feb. 21. The couple's first child Alexis, 22 months, was staying over at his parents.

Helga said the three officers were just amazing.

"I think (Jack's) hand is blue just from my hand squeezing his hand so hard," she laughed. Paulo, an accountant, admits his daughter will hear often how her father's lifeguard came to her rescue.

"I said to one of my friends 'This is a story I'm definitely going to be telling at Julia's wedding.'"

McGillivray called it a "once-in-a lifetime opportunity."

"Twenty five years ago I taught Paulo swimming lessons with the city culture and recreation. It was a neat experience to run into each other again and deliver his child," she said.

Acting Staff Sergeant Mark Petkoff said the Mountain squad was very pleased with the officers' response.

"We have a shift motto that 'Doing nothing is not an option' and they certainly lived up to that."

kpeters@thespec.com

905-526-3388