The first big bang of New Year's Eve has taken off, with an intergalactic-themed burst of fireworks at 9pm.
The explosion of lights and sound was accompanied by songs reminding people to ‘‘Live it up’’ and that ‘‘Anything could happen’’.
The water was awash in an alien-like green glow from the hundreds of fireworks around the harbour’s edge, as explosions that resembled spaceships, stars and planets burst into the air above the city.
World renowned: Sydney's 9pm fireworks did not fall short of expectation. Photo: Edwina Pickles
A spaceship with two little aliens took flight from the bridge to complete the 10-minute display.
The soundtrack for the fireworks featured 13 pieces of music, including Live It Up by Mental as Anything, Here's To Never Growing Up by Avril Lavigne and Anything Could Happen by Ellie Goulding.
The alien under the bridge. Photo: James Brickwood
But more than 100 New Year’s Eve revellers have been helped from two sinking boats in Sydney Harbour.
Police say 100 party-goers were rescued from a yacht near Garden Island about 8pm when the vessel began taking on water.
Circular Quay: Fireworks are let off under the Harbour Bridge in the 2013. Photo: Edwina Pickles
A water police boat took 60 people to safety, while another 40 found refuge on a nearby private boat.
Following the 9pm fireworks, some other on-water revellers had their evening disrupted when their boat started sinking at Farm Cove in front of Mrs Macquarie's chair.
A Fairfax Media photographer captured the image of the 30-foot yacht upturned in the water with the Harbour Bridge in the background.
The yacht sinking in the Harbour just in front of Mrs Macquarie's chair. Photo: James Brickwood
Water police were sent out to rescue the six passengers on board and all were unharmed, a police spokeswoman said.
About an hour before the 9pm family show, raindrops fell on the heads of those who had crowded onto the foreshore for the display - but meteorologists said it was just a passing shower.
Many of the best spots to view tonight's fireworks extravaganza filled up so quickly that they are were closed to potential skygazers from 5.30pm.
Areas around the Royal Botanic Gardens, Circular Quay and the north shore are full and closed to more people, a spokeswoman for the Transport Management Centre said.
Residents to the north of the Harbour Bridge say visitors are being turned away from Blues Point Reserve, which looks like "tent city" and where crowds of teenagers have gathered in previous years to watch the fireworks.
Those heading to the reserve at McMahons Point were being redirected to Bradfield Park under the Harbour Bridge at Kirribilli.
In Pyrmont, security guards are searching the bags of every person trying to cross the Pyrmont Bridge and making those who are carrying alcohol wait for an escort before they can cross.
In an effort to keep alcohol and glass away from the harbour's alcohol-free zones, private security guards and rangers are personally taking people who are carrying alcohol as far away as possible from the zones.
A spokewoman from the Sydney Harbour Foreshore Authority said this happened every year but the wait for people hoping to cross the bridge should not be more than 15 minutes.
The closures are causing many to change plans or turn to the television for a good view of the fireworks.
About 1.6 million people are expected to flock to Sydney's city centre for the fireworks shows at 9pm, the one-minute bonus fireworks at 10.30pm and the big hurrah at midnight.
The displays will include 11,000 aerial shells and 25,000 shooting comets that will explode from seven barges spread across six kilometres of Sydney Harbour.
For the first time in a decade, 1000 fireworks will also be shot from the top of the Opera House, as well as from the Harbour Bridge and from jet skis stationed in the harbour
Most of the road closures for the city are now completed or under way. The cycleways and pedestrian paths over the Harbour Bridge have also been closed.