MIAMI — At least 30 Haitians who tried to sail to the United States were found drowned on Tuesday after their overloaded boat ran aground off the Bahamas and capsized, several days after fishermen tipped off Bahamian military authorities about the vessel.

The Bahamian military had been unable to conduct air searches for the boat, a 40-foot sloop dangerously packed with immigrants, because all three of its planes were out of service, a defense spokesman said. The Royal Bahamas Defense Force conducted an unsuccessful search by sea and notified the United States Coast Guard about it on Monday afternoon, after six survivors who had paddled to shore on a raft were apprehended. They said the ship ran aground on Saturday.

About an hour after deploying a helicopter, the Coast Guard found the boat 15 nautical miles from Harvey Cay, and 20 miles from where the fishermen first reported seeing it. The spot is about 250 miles southeast of Miami.

About 60 people were clinging to the sailboat and dozens more were standing in waist-high water, the Coast Guard said. No one had life jackets. The passengers, at sea since Nov. 18, had run out of food and water.