* President forced out in 2012 hopes to be voted back in
* Unrest hurt nation's tropical paradise image
* If no outright winner, run-off scheduled for Sept. 28
By J.J. Robinson
MALE, Sept 7 (Reuters) - Voters in the Maldives thronged polling stations on Saturday to chose a new leader 20 months after their first democratically elected president was ousted, causing months of sporadic violence and uncertainty.
Mohamed Nasheed, forced from power in February 2012 in what his supporters say was a coup, hopes to return to office and end a period of unrest that has tarnished the Indian Ocean archipelago's image as a tropical holiday paradise.
"Voting today is significant because we are going to establish a legitimate government," he said after waiting 15 minutes to cast his ballot in the city centre, near police headquarters.
Jostled by reporters, Nasheed was whisked to the front of the queue by bodyguards and then quickly out of the polling station.
He is running against three rivals, including Mohamed Waheed Hassan Manik, who took over as president after his ouster.
But Nasheed's main rival is expected to be Abdulla Yameen, a half-brother of Maumoon Abdul Gayoom, the man who ruled for 30 years and was considered a dictator by opponents and rights groups.
"I hope to get through in the first round itself," Yameen told reporters.
Also on the ballot is Gasim Ibrahim, a resort tycoon, media business owner and a finance minister under Gayoom.
Voters waiting in queues that stretched around street corners in the capital Male, were eager to cast their ballots after the prolonged period of turmoil.
"I've been waiting 19 months for this day. So I got here as early as I could. It's my way of standing up against the coup," said Ismail Shiyaz, 39, a backer of Nasheed.
Others, like Rooya Hussain, were less certain.
"I don't think any of these candidates are suitable," she said. "However, I cast a valid vote for one of them. Let's see if this brings any change for the better."
Nasheed said he now enjoyed support in the ranks of the military and police which helped force him from office and expressed confidence he would secure 50 percent of the vote to win in the first round. A split vote would force a run-off on Sept. 28.
Nasheed was forced to resign in February 2012 after mutinying police and military forces armed opposition demonstrators and gave him an ultimatum.
His removal sparked unruly protests by his supporters and a heavy-handed police crackdown, pushing the country into crisis. A Commonwealth-backed commission of inquiry later concluded that his removal did not constitute a coup.
A rise in Islamist ideology, human rights abuses and a lack of investor confidence after Waheed's government cancelled the country's biggest foreign investment project with India's GMR Infrastructure are among the critical issues the new president will face.
The Maldives, a sultanate for almost nine centuries before becoming a British protectorate, held its first fully democratic
polls in 2008 with Nasheed defeating Gayoom, an autocrat who was then Asia's longest-serving leader. (Additional reporting and writing by Shihar Aneez in Colombo; Editing by Ron Popeski and Robin Pomeroy)