By Amy Tennery

RIO DE JANEIRO (Reuters) - The seemingly unstoppable American women's eight rowing team launch their quest for another Olympic gold medal when the heats get underway on Monday with a possible dynasty in the making.

The U.S. have claimed gold in the past two Olympics and underlined their dominance of the event by winning a 10th consecutive world title at the 2015 World Rowing Championships in Aiguebelette, France, last September.

Matthew Pinsent, Britain's four-time Olympic gold medal rower, called the U.S. women's eight the "most dominant outfit in world rowing at the moment".

"It has a sort of gravitational pull within the rowing (community)," Pinsent said. "It attracts the best people."

Pinsent pointed to the boat's high turnover rate as evidence of the exacting standards and high level of performance required to make the squad.

"No seat is ever really safe," he said.

Just two of this year's crew are returning Olympians: Eleanor Logan, 28, who competed in both the 2008 Beijing Games and the 2012 London Games, and Meghan Musnicki, 33, a member of the eight crew in London.

The success story began after Tom Terhaar became the women's head coach at the U.S. rowing federation (USRowing) in 2001.

Terhaar, who declined an interview request, led the women's eight to a silver medal in Athens in 2004, the first medal the U.S. had won in the event in two decades.

USRowing high performance director Curtis Jordan told Reuters the boat operated on a "very systematic" basis.

"The athletes and the coaches go about their business knowing that everybody's beatable," Jordan said. "If you don't do your homework and you don't do what you’re supposed to, you're going to get beaten."

Jordan pointed to Canada, the Netherlands and Britain as the boat's possible top challengers, citing strong programs in all three countries.

David Tanner, British Rowing's performance director, told Reuters that their team were "confident and grounded" going into the Games.

"If you don’t believe you can challenge a boat like (the U.S.) then you’re not going to be on the podium yourself," Tanner said.

(Editing by Brian Homewood)