GREENE – It will bring throngs of fans to Boston this weekend. Interest will be high and the hype will be immense. The excitement and tradition of the event might be like no other.

It’s something Marlo Welsh has anxiously awaited all summer.

“Every year this is the main event of the fall,” said Welsh. “It’s something we all look forward to.”

It may not be what you think.

The Head Of The Charles regatta draws 7,000 rowers annually to the two-day event. In its 40th year, it is the largest rowing competition in North America.

“The whole city of Boston is involved,” said Welsh, a personal trainer at Bates College. “Everyone comes. It’s an event for the entire city. That makes it that much more exciting. There’s thousands and thousands of people lining the course.”

Welsh will be competing late Saturday afternoon in the Women’s Doubles race, just hours before the World Series begins not far from the Charles River.

“The same possibility happened last year,” said Welsh, who has rowed in the Head of the Charles over a half dozen times. “We were kind of wondering if it would have been really crazy because the day of the regatta would have been Boston’s first game after beating the Yankees. We were wondering how that was going to be.”

Welsh and her rowing partner, Vanessa Thorne, get to find out this time. Thorne’s coming up from Pomfret School in Connecticut where she’s a rowing coach. The two met rowing in an Eight together years ago and often team up for doubles races. Welsh took time off during the summer. So the opportunity to pair up has been limited this year.

“It is a social thing, to get together with her and see her,” said Welsh. “The race, we just want to row together again. She was really upset with me that I didn’t row this summer. She wanted to row with me, and she was trying to convince me all year to row, but I was like, I need a break from rowing.'”

Welsh has been an athlete since the age of seven. She competed in gymnastics until she was 18, but during that time, she was drawn to rowing, surrounded by the sport growing up in St. Catharine’s, Ontario.

“So when I decided I’d had enough of gymnastics, I still needed something,” she said. “I’d always been very physical and athletic.”

She rowed in high school and college but has competed more frequently after finishing school. She’s not as fierce a competitor as she once was, but the lure of the sport still remains.

“It’s the same thing that got me in the first place,” said Welsh. “I don’t know how to describe it. It’s a beautiful sport. The atmosphere on the water, being outside, with the water and the gorgeous colors like this in the fall. I’ve always been very physical, and it’s a physical sport. I love the way it keeps me in shape.”

She says even if she wasn’t competing, she’d still row. She met her husband, Mark, through rowing in St. Catharine’s. He’s an assistant rowing coach at Bates.

She’ll typically train daily through the summer and fall, often even twice per day. She’ll usually race every weekend in the summer and take in four or five regattas in the fall.

This summer her boat needed repair, and she needed a break. Now she’s back from a hiatus with new vigor.

“I’ve enjoyed it more,” she said. “Last fall was a struggle because that’s when I was kind of burning out of competing. This fall, I’ve had more of a relaxed attitude about it too – just kind of go out and be fit and have some fun and see where it gets you in the race.”

That’s how Welsh and Thorne look at this weekend’s race. They’ll be in a competitive class of rowers and hope to hold their own.

With Welsh training on her own on the Androscoggin River and Thorne in Connecticut, it makes it tough for the two to prepare as a team. Welsh says she just train to stay fit and prepare herself for the eight-kilometer course.

“Generally, it’s a tough thing to do,” said Welsh. “When you’re in a boat with someone else, you really should be training together. Vanessa and I have been rowing together for eight years.

“From the first day we were in a double together, there was a chemistry that happens with someone else. Technically, if we really wanted to go out and win this race and do really well, we should train together every day regardless of how well we click. But we’re more or less just doing this for fun and to get together again and row.”