By Irene Klotz

MELBOURNE, Florida (Reuters) - Tropical Storm Fay dumped torrential rain on central Florida on Wednesday, flooding streets in knee-high water as it stalled over the U.S. space shuttle fleet's home port at Cape Canaveral.

Hundreds of homes were affected, some flooded under 4 feet (1.2 metres) of water, and emergency teams in airboats and boats spread out to rescue people as up to 21 inches (53 cm) of rain came down in a day, officials said.

"We've had a lot of flooding in isolated neighbourhoods, people with anywhere from 6 inches (15 cm) to 4 feet (1.2 metres) of water in their homes," said Erick Gill, public information officer for St. Lucie County, just north of West Palm Beach.

"We've had just under 1,000 homes impacted by the flooding. We've had to rescue people in boats and airboats," Gill said. An airboat is a flat-bottomed vessel with an airplane propeller at the back and is useful in shallow water and swamps.

In Brevard County, where the Kennedy Space Center is located, emergency management spokeswoman Kimberly Prosser said some places had registered 21 inches of rain since Fay came ashore on Florida's southwest coast on Tuesday.

"We're getting beat on and beat on and beat on. It's still over us," said Deputy Jeff Luther, a spokesman for the emergency operations centre and the sheriff's office in Indian River County, just south of Brevard.

The storm, which killed more than 50 people in the Caribbean before churning over Cuba, the Florida Keys and then reaching the Florida peninsula, was about 30 miles (45 km) north-northeast of Cape Canaveral by 5 p.m. (2100 GMT), the U.S. National Hurricane centre said.

It was moving north at an excruciatingly slow 2 miles per hour (4 kph), meaning it would keep soaking central Florida for some time.