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.
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.