Summary:
The South Korean coastguard has said a boat that got stuck on the seabed was a rescue operation.

Full article:
(CNN) -- After more than 12 hours stuck at sea, passengers aboard a whale-watching boat off the Massachusetts coast reached shore and safely docked in Boston on Tuesday morning, the Coast Guard said. The 163 people aboard the Cetacea found themselves stuck after a line got tangled in the vessel's propeller Monday afternoon, the Coast Guard said in a statement. The 83-foot boat was about 13 miles (21 kilometers) east of Nahant, Massachusetts. On Tuesday morning, the line entangling the propeller was released, Coast Guard Petty Officer MyeongHi Clegg said. The boat docked at the Long Wharf in Boston, Clegg said. Three Coast Guard crews had been on the scene, with one vessel offering medical support as needed. Clegg said two people had become sick, but their illnesses were not considered serious. Coast Guard members and Boston Harbor Cruises conducted checks to ensure the boat's safety before it headed back to shore, Clegg said. The Coast Guard vessel Tybee helped escort the boat.