An 18-foot aluminum boat capsized Wednesday in cold, choppy Chesapeake Bay off Virginia Beach, killing two people aboard and sending four others to hospitals, police said.

Virginia Beach police spokesman Adam Bernstein said the six boaters, whom authorities have not identified, departed from the Lynnhaven Boat Ramp and Beach House and phoned in a distress call to the Coast Guard shortly before 9 a.m.

A Coast Guard helicopter crew rescued two of them and the others were recovered by boat, Coast Guard spokesman Kip Wadlow said.

The National Weather Service said the water temperature was 46 degrees at the Chesapeake Bay Bridge-Tunnel. It also had issued a small-craft advisory, with waves up to 5 feet high and strong winds.

Two boaters taken to Sentara Norfolk General Hospital were listed in good condition Wednesday afternoon, said spokeswoman Emma Inman.

The two people who died were among the four taken to Sentara Virginia Beach General Hospital. One survivor was in critical condition, the other in fair condition, Inman said.

Authorities have recovered the boat and are investigating.