The US Coast Guard has seized the dinghy missing Florida woman Lynette Hooker was riding when she vanished into Bahamian waters in early April, as investigators step up their probe.

On the evening of April 4, Lynette and Brian Hooker were aboard a dinghy in the Bahamas making their way to the sailboat they lived on, “Soulmate.”

After six days of searching by police and volunteers, authorities announced that a child's body dressed in “similar clothes” was found Thursday in an out-of-the-way location on a farm in the southwest...