A large navigation aid maintained by the United State Coast Guard sank and disappeared in the Wrangell Narrows near Petersburg, Alaska. The Coast Guard issued a bulletin informing seamen that it had conducted dragging operations and the navigation aid “was not present above the contour of the natural bottom of” the channel. Nevertheless, Otness’s (plaintiff) ship collided with the navigation aid. Otness sued the United States government (defendant) under the Federal Tort Claims Act, alleging that the Coast Guard’s negligence in issuing the bulletin proximately caused the damage to his ship. At the close of evidence, Otness moved for leave to amend his complaint under Federal Rule of Civil Procedure (FRCP) 15(b) to add a claim of “willful, wanton, or reckless” conduct by the Coast Guard, arguing that adding the additional claim could not prejudice the government on the ground that its defense to negligence was equally applicable to claims of willfulness, wantonness, or recklessness.