The M/V Capetan Yiannis, a freighter, was damaged and temporarily put out of service in an accident in the Port of Milwaukee on Lake Michigan. The owner of the ship, Brotherhood Shipping Company, brought suit against the charterer (i.e., lessee) of the ship, Afram Lines, and also against the City of Milwaukee, which owns the port, and the city's insurer, seeking damages for the damage to the ship and for the loss of revenues from the ship's being out of service because of the accident. The plaintiff designated the suit as one in admiralty, in accordance with Rule 9(h) of the Federal Rules of Civil Procedure. The city counterclaimed for the damage that the accident had caused to the slip in which the ship was berthed at the time of the accident. Both the claim against the charterer and the counterclaim against the shipowner remain pending in the district court. The shipowner's principal claim against the city (and its insurer--for Wisconsin is a direct-action state--but we can ignore the insurer), and the only one we need discuss, is that the city was negligent and its negligence contributed to the accident. The district judge granted the city's motion for summary judgment and dismissed the shipowner's claims against it. Since other claims remain pending in the district court, this was a partial dismissal only, making the shipowner's appeal interlocutory. But as orders resolving the rights and liabilities of parties to admiralty cases are appealable as of right even if interlocutory, 28 U.S.C. § 1292(a)(3), our jurisdiction is secure.

The only issue for us is whether, viewing the evidence obtained through pretrial discovery as favorably to the shipowner as reason allows, we can say that no reasonable trier of fact could conclude that the city had been even a little bit negligent. It is important to emphasize that this is the only issue, because the appellees' strategy in argument has been to direct our attention elsewhere. They argue that because this is a suit in admiralty and therefore to be tried by the judge rather than by a jury, we should permit the judge greater latitude in finding facts on summary judgment than we would if, were the case to be tried, the trier of fact would be different, would be a jury. And they argue that, even if the city was negligent, the captain of the Capetan Yiannis, and other persons who may (or may not) have been the shipowner's agents, were themselves negligent--and far more so than the city.

The first point is wrong, and the second irrelevant. Take the second first. The rule in admiralty, when property damage results from a collision between two ships, or, as here, between ship and shore, is comparative negligence (equivalently, relative fault). The plaintiff's negligence reduces the amount of damages that he can collect, but is not a defense to liability. United States v. Reliable Transfer Co., 421 U.S. 397, 95 S. Ct. 1708, 44 L. Ed. 2d 251 (1975). Now in many states that embrace comparative negligence the plaintiff's negligence remains a defense to liability if he fails to prove that the defendant's negligence was more than 50 percent responsible for the accident. Wisconsin is such a state. Wis.Stat. § 895.045. And the appellees urge us to apply Wisconsin's rule. But admiralty is not merely a basis of jurisdiction, like diversity of citizenship. It is a body of substantive principles as well, or more precisely a grant of power to federal judges to create a body of admiralty law, much as section 301 of the Taft-Hartley Act, 29 U.S.C. § 185, has been interpreted as a grant not only of federal jurisdiction to enforce collective bargaining agreements but also of judicial authority to formulate federal rules of decision. Textile Workers Union v. Lincoln Mills, 353 U.S. 448, 456, 77 S. Ct. 912, 918, 1 L. Ed. 2d 972 (1957). One of the judge-made substantive admiralty rules is the doctrine of comparative negligence, which in its original form as divided damages was invented in admiralty and applied there long before it became a part of the common law of torts through common law evolution and statutory intervention. (See also Pope & Talbot, Inc. v. Hawn, 346 U.S. 406, 408-09, 74 S. Ct. 202, 204, 98 L. Ed. 143 (1953), applying comparative negligence in personal-injury suits brought in admiralty long before most states had adopted comparative negligence.) The admiralty doctrine of comparative negligence, unlike some state comparative-negligence statutes, has never had a threshold above which a plaintiff's negligence barred all recovery. We do not understand the city to be arguing that we should create such a threshold. It argues, erroneously, that we should apply Wisconsin law, which contains the threshold; but it does not argue that if we reject Wisconsin law we should create a new doctrine of admiralty law. As we are given no reason to depart from the "pure" comparative negligence standard (illustrated in admiralty by our decision in Cement Division v. City of Milwaukee, 915 F.2d 1154 (7th Cir.1990), and outside of admiralty by many cases, such as Lamborn v. Philips Pacific Chemical Co., 89 Wash.2d 701, 705, 575 P.2d 215, 219 (1978) (en banc); Villa v. Crown Cork & Seal Co., 202 Ill.App.3d 1082, 1084, 148 Ill. Dec. 372, 374, 560 N.E.2d 969, 971 (1990), and our Wassell v. Adams, 865 F.2d 849, 852 (7th Cir.1989)), we shall assume that if the plaintiff's negligence is deemed 99 percent responsible for the accident in this case and the defendant's negligence 1 percent responsible, the plaintiff is entitled to 1 percent of its damages.

Of course, if the plaintiff's negligence is such that the accident would have occurred even if the defendant had not been negligent at all, the plaintiff cannot recover, having failed to show a causal relation between the defendant's negligence and the accident, an essential element in a tort suit. But it is not clear from the evidence gathered in discovery in this case that the accident would have happened even if the city had exercised due care; so we may disregard it as a possibility in this appeal.

As for the fact that the case, if tried, would be tried by the judge who issued the order now under review by us granting summary judgment, it is not even clear that this is a fact. Setting aside every contingency that may cause a different judge to preside at a trial from the one who ruled on a motion for summary judgment, we point out that even a case within the admiralty jurisdiction is sometimes triable to a jury. Under the "saving to suitors" clause in the statute that specifies the admiralty jurisdiction of the federal courts, 28 U.S.C. § 1333(1), an admiralty plaintiff is entitled to pursue any other remedies that he might have as well as his remedies in admiralty. In this case, the requisites for diversity jurisdiction appear to be satisfied, and the plaintiff demanded a jury trial, to which the Seventh Amendment would entitle it in a diversity case in which damages are sought. While the plaintiff might not get far under Wisconsin tort law, for the reason already suggested (the difference between Wisconsin and admiralty comparative-negligence law), Wisconsin tort law would not apply. Admiralty law, and hence the admiralty rule on comparative negligence, furnishes the rule of decision in any case within the admiralty jurisdiction, even if it is within the diversity jurisdiction as well so that the plaintiff is entitled to demand a jury. Pope & Talbot, Inc. v. Hawn, supra, 346 U.S. at 410-11, 74 S. Ct. at 205-06; Harville v. Johns-Manville Products Corp., 731 F.2d 775, 779 (11th Cir.1984).

What is true is that by pleading its claim as one in admiralty--for reasons, incidentally, that are wholly unclear--the plaintiff may well have waived the right to a jury trial that it would have had if it had forgone a Rule 9(h) designation and based jurisdiction instead on diversity of citizenship. T.N.T. Marine Service, Inc. v. Weaver Shipyards & Dry Docks, Inc., 702 F.2d 585 (5th Cir.1983) (per curiam); Romero v. Bethlehem Steel Corp., 515 F.2d 1249, 1253 (5th Cir.1975); 9 Charles Alan Wright & Arthur R. Miller, Federal Practice and Procedure § 2315 at p. 76 (1971); see also Note, "The Jury on the Quarterdeck: The Effect of Pleading Admiralty Jurisdiction When a Proceeding Turns Hybrid," 63 Tex. L. Rev. 533, 539-40 (1984). The plaintiff's decision to plead its case as an admiralty case cannot be dismissed as a formality, when already the plaintiff has used the distinctive procedures of admiralty to take this interlocutory appeal. We doubt profoundly that in these circumstances the district judge would--or should--be receptive to a motion under Rule 15 to amend the complaint by withdrawing the plaintiff's Rule 9(h) designation (though Rule 9(h) authorizes such motions) so that the plaintiff can have the best of both procedural worlds. But that is a side issue. The pertinent point is that there can be no certainty, even in a case within the admiralty jurisdiction, that the judge who grants summary judgment will, if his decision is reversed, be the trier of fact at trial. And in any event the care with which we review a grant of summary judgment ought not vary with the likelihood that if we reverse, the judge we are reversing will be the trier of fact on remand and will use his factfinding discretion to reinstate the judgment that we have reversed. Even realism has its limitations. It is no doubt inevitable that a reviewing court will give more or less weight to a district judge's discretionary determinations depending on the respect in which the court holds the particular judge. It is neither inevitable nor desirable that the reviewing court should give more weight to a grant of summary judgment because the plaintiff has not asked for, or is not entitled to, a trial by jury if he clears the hurdle of summary judgment. For one thing such a differentiated standard of review would encourage plaintiffs to demand a jury trial where otherwise they might have been content with a bench trial. For another thing it would require us to get entangled in subtle issues, well illustrated by this case, concerning the right to a jury trial.

From time to time courts have hinted, though none to our knowledge has held, that if no jury trial is in the offing the trial judge can go beyond the strict scope of summary judgment--an inquiry into the existence of a genuine issue of material fact--and do a little factfinding. Houston North Hospital Properties v. Telco Leasing, Inc., 680 F.2d 19, 22, on rehearing, 688 F.2d 408 (5th Cir.1982); Tripp v. May, 189 F.2d 198, 200 (7th Cir.1951). Today we reaffirm that he may not. United States v. Bosurgi, 530 F.2d 1105, 1110, 1112 (2d Cir.1976); 10A Charles Alan Wright, Arthur R. Miller & Mary Kay Kane, Federal Practice and Procedure § 2728 at pp. 178-87 (1983). Of course if trial is to the court and the judge elects to proceed under Fed.R.Civ.P. 42(b) and try a discrete issue separately, that abbreviated "trial" may closely resemble a summary judgment proceeding, especially since a judge has a limited power to hear oral testimony in aid of determining whether there are any issues of fact that would prevent the grant of summary judgment. (Both points are discussed in Stewart v. RCA Corp., 790 F.2d 624, 628-29 (7th Cir.1986).) That is not this case. And litigants can, if they want, waive the right to a trial and treat the summary judgment proceeding as the trial, May v. Evansville-Vanderburgh School Corp., 787 F.2d 1105, 1115 (7th Cir.1986); Market Street Associates Limited Partnership v. Frey, 941 F.2d 588, 590 (7th Cir.1991), and then the judge should make factfindings just as he would in a real trial. That is not this case either.

So we come back to where we began: The sole issue for us is whether, viewed as favorably to the plaintiff as is reasonable, the evidence gathered in pretrial discovery would, were the same evidence to constitute the entire record at trial, warrant a finding that the city was negligent. In answering that question, we apply the standard of negligence laid down by Judge Hand in the famous admiralty case of United States v. Carroll Towing Co., 159 F.2d 169, 173 (2d Cir.1947), endorsed by this court as the proper admiralty standard in United States Fidelity & Guaranty Co. v. Jadranska Slobodna Plovidba, 683 F.2d 1022 (7th Cir.1982), and cited approvingly by other courts in admiralty cases, as well. E.g., In re Complaint of Paducah Towing Co., 692 F.2d 412, 422 n. 18 (6th Cir.1982); Louisiana ex rel. Guste v. M/V Testbank, 564 F. Supp. 729, 740-41 (E.D.La.1983); Pruitt v. Allied Chemical Corp., 523 F. Supp. 975, 978 n. 11 (E.D.Va.1981); Selame Associates, Inc. v. Holiday Inns, Inc., 451 F. Supp. 412, 419 (D.Mass.1978); cf. East River S.S. Corp. v. Transamerica Delaval Inc., 476 U.S. 858, 872 (1986); Andros Shipping Co. v. Panama Canal Co., 298 F.2d 720, 726 (5th Cir.1962). Under that standard, a defendant is negligent if the burden (cost) of the precautions that he could have taken to avoid the accident (B in Hand's formula) is less than the loss that the accident could reasonably be anticipated to cause (L), discounted (i.e., multiplied) by the probability that the accident would occur unless the precautions were taken. So: B