A Coast Guard helicopter spotted a large boat on Tuesday off the coast of Florida, but it was too late to locate the boat, which was last seen Friday morning.
The Coast Guard said it launched a search for the boat about 1 p.m.
ET, but had yet to locate it.
The search area extends about 100 miles (160 kilometers) southwest of Jacksonville, according to a Coast Guard news release.
The boat was spotted by a Coast Guards helicopter about 1:30 p.ms.
ET off the northwest coast of Lake Erie near the mouth of the Erie Canal, the Coast Guard wrote in the news release, adding that there were no other boats or signs of life.
The agency said it was not yet known if the boat was a large, commercial or recreational boat.
The rescue team was able to find the boat by using sonar to search for signs of movement.
The coast guard said it would not disclose the nationality of the boat owner, who was not immediately identified.
The Coast Guard added that there was no danger to the public.
A search is ongoing.