“Up!”

“Split!”

“Turn around!”

Is it a dance team practicing?

No, just Yale’s female rowing team lifting their 58-foot-long, 210-pound row boat.

The Head of the Charles, the world’s largest rowing regatta, kicked off Friday, Oct.,Commanding shouts were heard on the Charles River last weekend.

“Up!”

“Split!”

“Turn around!”

Is it a dance team practicing?

No, just Yale’s female rowing team lifting their 58-foot-long, 210-pound row boat.

The Head of the Charles, the world’s largest rowing regatta, kicked off Friday, Oct. 20 with a laser light show and continued through the rest of the weekend.

The organizers expected 250,000 spectators to follow the events and, thanks to the good weather and a clear blue sky, their expectations appeared to be satisfied. Many people gathered on the bridges and banks of the Charles River to watch the rowers as they moved in perfect unison back and forth while the boats slid gracefully through the water.

The starting line of the course was by the BU Bridge and the finish line was three miles upstream at Herter Park in Brighton. The boats passed Cambridge, the areas around Harvard Square, Allston and Harvard University.

Near the water’s edge, Fabrizia Adang, 21, and her friend Vicky Bird, 21, both students at Wellesley College, enjoyed the race in the autumn sun. It was the third time Fabrizia had been a spectator at Head of the Charles.

“It’s fun to watch the rowers,” Adang said. “It’s a nice atmosphere and a lot of people. It’s very relaxing.”

“Head” races are a class of regattas, generally three miles long. Winners of each race receive the honorary title of “Head of the River.” In Boston, the winners of each event are dubbed “Head of The Charles.”

Head races are unique as rowers start in a single file, one after another, instead of side-by-side. The boats start 10 to 15 seconds apart from each other. It takes approximately 15 to 21 minutes for the largest boat to get from start to finish.

The Cambridge Boat Club has organized this annual event since 1965. During the first year’s race, fewer than 100 rowers participated, but the event has grown tremendously.

This year, 8,200 rowers from 40 states and 16 countries participated. In total, 1,600 boats competed in 52 events, in everything from Championship Doubles to Veteran Singles, for people over the age of 60, and races for those under the age of 20.

Ten percent of all 164 boat entries this year were international. Competitors came from China, Canada, Australia, Italy and South Africa, just to name a few.

Linn Dobrowolski, 22, from Amsterdam, was visiting Boston for the first time. She competed in a boat with eight rowers from her club, A.A.S.R. Skoll, during Sunday’s race.

“It’s really good being here,” Dobrowolski said. “Interesting people, I like the rowing, and the weather is very nice. I like the city too. We have a lot of good rowing teams in Holland, but people are not so interested. This is so big and there are much more people watching here.”

“We also have a Head of the River in Amsterdam, Head of the River Amstel, with curves and such just like here, but this is much more exciting because it’s bigger,” she added.

The race is not only for those that love rowing, but also for anyone who wants to have a good time. On the riverbanks along the racecourse, organizers arranged a lot of activities to entertain spectators.

Near John W. Weeks Bridge on the Cambridge side, close to Harvard Square, a large scene provided the audience with up-and-coming national artists as well as local favorites.

A lot of people gathered on the riverbank between the Weeks Bridge and Larz Anderson Bridge, where endless sponsors tried to sell everything from health food to cars.

Watching the rowers was only half the fun; it was an occasion for families and friends to strengthen their bonds. Autumn made its presence known with a biting wind, but that did not prevent families, friends and couples to have a nice weekend picnic.

Lance and Agnieszka Toble had filled their blanket with popcorn, nuts, cake and a stereo. Together with friends, they have watched Head of the Charles for five years in a row.

“It has become like a tradition,” Toble said. “It’s my wife’s birthday and we got married during Head of the Charles, so this is like an anniversary.”