(Updates throughout)

PARIS, Aug 8 (Reuters) - The Olympic women's 10km marathon swimming event started on schedule on Thursday after water-quality tests in the Seine river met thresholds.

More than 30 medals will be on offer, including in athletics and sailing while finals will be held in boxing, taekwondo, wrestling and track cycling.

Here's what you need to know about the Olympics on Thursday:

MARATHON SWIMMING

Brazil's defending champion Ana Marcela Cunha and swimming rivals in the gruelling event dived off a platoon by the Alexandre III bridge at 7:30 a.m. (0530 GMT) and swam furiously toward the Pont de l'Alma.

The race features a 1.67km loop completed six times between the two bridges on the river flowing through the French capital.

SPRINT DOUBLE FOR LYLES?

The newly minted world's fastest man, Noah Lyles, takes to the track again aiming to complete the prestigious sprint double by adding the 200 metres title to his 100m victory last week.

If he succeeds, Lyles will be the first American to achieve the sprint double since Carl Lewis in 1984.

CARRINGTON IN HUNT FOR SEVENTH MEDAL

The first medals in the canoe sprint are up for grabs and Lisa Carrington, New Zealand's most successful Olympian, will look to add to her impressive haul of five golds and a bronze when she takes part in the women's kayak four 500m.

HALL SNATCHES GOLD IN THE 400M

In athletics, Quincy Hall produced an incredible late surge to overhaul Briton Matthew Hudson-Smith and take a first Olympic 400 metres gold for the United States since 2008 in another scintillating and dramatic race on Wednesday.

TAIWAN'S LIN EASES INTO WOMEN'S BOXING FINAL

Taiwan's Lin Yu-ting, one of two boxers at the centre of a gender dispute at the Paris Olympics, moved a step closer to the Olympic title when she beat Turkey's Esra Yildiz by unanimous decision in the women's featherweight semi-finals on Wednesday.

Over in New York, diplomatic punches between Russia and Algeria were being thrown over the issue during a meeting of the body focused on women, peace and security.

HOT PURSUIT

Australia won a thrilling men's team pursuit final on Wednesday against Britain at the National Velodrome to claim their first Olympic gold medal in the iconic cycling event since 2004. In the women's event, the United States took gold for the first time ever, beating New Zealand.

(Compiled by Ingrid Melander, Rachel Armstrong, Rohith Nair; Editing by)