Lucas failed to complete the first of the 10-race series but recovered to win seven of the next nine.
The 40-year-old is the only confirmed member of the British Paralympic team for the Rio Games.
"It's been a really good regatta and great to start 2016 off with a win," she said.
"We have had some great winds and some good conditions in different directions which has made it a good regatta."
The Sonar crew of John Robertson, Hannah Stodel and Stephen Thomas missed out on a medal by finishing fourth.
The trio were second behind Canada going into the final day but three fifth places ended their medal hopes.

The motoring organisation also called for extra funding for road repairs in the chancellor's Budget next week.
The Local Government Association (LGA) said there was a £12bn backlog in road repairs that would take councils "more than a decade" to clear.
The UK government said it was providing "unprecedented levels of investment".
In an AA survey of 25,208 drivers, 39% said their tyres, bodywork or other parts of their vehicles had been affected after hitting a pothole in the past two years.
AA president Edmund King called on local authorities to "get to grips with fundamental road maintenance" such as poor drainage and crumbling surfaces.
He also said Chancellor George Osborne should allocate extra funding for road repairs to "reverse the toll on vehicles and their owners' pockets".
LGA transport spokesman Peter Box said current funding levels and the repairs backlog meant councils "can only keep pace with patching up our roads and filling potholes".
"Long-term and consistent investment in local road maintenance is desperately needed," he added.
Road maintenance is devolved to England, Scotland, Wales and Northern Ireland.
Transport Minister Andrew Jones said the government had allocated a "record £6bn to councils in England to improve local roads over the next five years".
"We topped this up with £250m last year specifically to tackle the blight of potholes," he said.
A Scottish Government spokesman said in the last financial year more than £220m was allocated for the maintenance of motorways and trunk roads, which it said was 20% more than five years ago.
The Welsh and Northern Irish authorities have been approached for comment.
Britain's Helena Lucas finished with three wins out of three to secure overall victory in the 2.4mR event at the Sailing World Cup in Miami.
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The AA is calling on councils to "get to grips" with road maintenance after a survey found 39% of UK drivers reported pothole damage in the past two years.