New York Marine & General Ins. v. Continental Cement Company, was an action to determine coverage for a sunken barge where the insurer denied coverage on the ground the insured had failed to disclose the condition of the barge as required by the insured’s duty to exercise the utmost good faith. The district court did not err in determining that the doctrine of utmost good faith is such a judicially established federal admiralty rule that it applied to this maritime insurance dispute rather than Missouri state law; defendant waived its appeal of the denial of its motion for judgment as a matter of law on the insurer’s utmost good faith defense by failing to file a post-verdict motion under Rule 50(b) after the district court denied its Rule 50(a) motion; assuming defendant did not waive its challenge to the jury instruction on the defense of utmost good faith, the instruction adequately and fairly presented the issues, including the question of whether the undisclosed facts were material to calculation of the risk and the terms of the coverage.