Farrell Lines, Inc. (“Farrell”) appeals from a decision and order of the United States District Court for the Southern District of New York, Charles L. Brieant, Jr., Judge, finding Farrell liable for injuries sustained by appellee Anthony Canizzo in an accident on board Farrell’s ship, the S.S. African Comet. The court found Farrell liable for damages in the net ¿mount of $65,628.60, after a deduction which included $8500 per year for remaining earning ability and 40% contributory negligence, and Canizzo cross-appeals from this reduction in the damage award.
For the reasons adduced below, we affirm in part and reverse in part the judgment of the district court and remand the case for further proceedings consistent with this opinion.
I.
This suit commenced with the filing of a complaint against Farrell and Universal Terminal and Stevedoring Corp. (“Universal”), an independent stevedore loading cargo on board the African Comet on the day of the accident. Farrell impleaded Frank J. Holleran, Inc., Canizzo’s employer, as a third-party defendant, and filed a cross-claim against Universal. Universal then filed a cross-claim against Holleran. The district court dismissed Canizzo’s action against Universal, Farrell’s cross-claim against Universal, Farrell’s third party complaint against Holleran and Universal’s cross-claim against Holleran.
*684On January 12, 1973, the day of the accident, Universal was employed by Farrell to load the African Comet. Holleran provided lashing and carpentry personnel to secure the cargo after it was loaded by Universal. Canizzo worked for Holleran as a carpenter. At approximately 5:00 p. m. Canizzo was instructed to move from one part of the ship to another in order to continue his work. In so doing, he was forced to traverse a narrow passageway between a locomotive stowed on the inshore area of the deck and a nearby hatch coaming. While walking through this passageway, Canizzo slipped on a patch of grease which was partially covered by a pile of wires which lay on the deck. Canizzo sustained permanent injury to his knee, and as a result, is unable to work as a marine carpenter or longshoreman. He is not, however, totally disabled.
The trial court found that the ship’s crew placed cluster lights and their attached electrical wires in the passageway in question after 4:00 or 4:30 p. m., but at least one-half an hour before Canizzo’s accident. The lights, wires, and other clutter which lay on top of the greasy deck created an “obviously dangerous” condition which would have been obvious to any prudent person. The court found that Farrell had actual or constructive notice of this condition inasmuch as the ship’s personnel should have seen the grease on the deck when they put out the cluster lights. Furthermore, the crew should have anticipated that Canizzo would be unable to avoid the dangerous condition on the deck. This, the district court believed, was sufficient to bring Farrell within the negligence standard of § 343A of the Restatement (Second) of Torts (1965),1 which was adopted in this court’s opinion in Napoli v. [Transpacific Carriers Corp.] Hellenic Lines, 536 F.2d 505 (2d Cir. 1976).
The court found further, however, that Canizzo had been contributorily negligent in failing to walk with sufficient caution, or alternatively, in failing to avoid the wires by taking a different route to the No. 6 hatch. It was further held that Canizzo’s damages were reduced, inasmuch as he was capable of earning $8500 per year. Accordingly, the trial court awarded Canizzo $109,-381.00 reduced by reason of contributory negligence to $65,628.60.
II.
This suit is brought pursuant to the Longshoremen’s and Harbor Workers’ Compensation Act (“LHWCA”), 33 U.S.C. § 901 et seq., as amended. Amendments to the Act passed in 1972 increased levels of compensation payable to injured longshoremen, eliminated the doctrine of unseaworthiness as it pertained to shipowners, made a shipowner’s negligence a necessary condition of his liability, and immunized independent stevedore-employers from liability in excess of compensation payments. In the words of the House Report:
The Committee believes that where a longshoreman or other worker covered under this Act is injured through the fault of the vessel, the vessel should be liable for damages as a third party, just as land-based third parties in non-maritime pursuits are liable for damages when, through their fault, a worker is injured.
[But] the Committee believes that especially with the vast improvement in compensation benefits which the bill would provide, there is no compelling reason to continue to require vessels to assume what amounts to absolute liability for injuries which occur to longshoremen . who are injured while working on those vessels.
*685Accordingly ... it would be fairer to all concerned . . . for the liability of vessels as third parties to be predicated on negligence, rather than the no-fault concept of seaworthiness.
[Report of the House Education and Labor Committee, H.R.Rep.No.92-1441, 92nd Cong., 2d Sess., 1972 U.S.Code Cong. & Admin.News, p. 4698 at 4702-03.]
See Lubrano v. Royal Netherlands Steamship Co., 572 F.2d 364 (2d Cir. 1978); Ruffino v. Scindia Steam Navigation Co., 559 F.2d 861 (2d Cir. 1977); Munoz v. Flota Merchante Grancolombiana, S.A., 553 F.2d 837 (2d Cir. 1977); Napoli v. Transpacific Carriers Corp., supra, 536 F.2d 505; Landon v. Lief Hoegh & Co., 521 F.2d 756 (2d Cir. 1975), cert. denied, 423 U.S. 1053, 96 S.Ct. 783, 46 L.Ed.2d 642 (1976).
Under the relevant provisions of the Restatement (Second) of Torts (1965), possessors of land, and hence shipowners, are liable for physical harm caused to invitees by dangerous conditions which are not obvious to the invitee (§ 343), but are absolved from liability when dangerous conditions are known or obvious, except when the possessor should anticipate the harm despite the invitee’s knowledge or the obviousness of the condition. (§ 343A.)
Thus in Napoli, supra, we held that where a longshoreman had fallen from unsecured planks, there was sufficient evidence of the shipowner’s knowledge of “obviously dangerous conditions” that were unlikely to be avoided by the longshoreman, that the case should have gone to a jury for a determination of the shipowner’s negligence under § 343A of the Restatement (Second) of Torts. 536 F.2d 505.
A shipowner, however, can only be liable under § 343A if he knows or should have known of the obviously dangerous, but unavoidable, condition. Ruffino v. Scindia Steam Navigation Co., supra, 559 F.2d at 862; Munoz v. Flota Merchante Grancolombiana, S.A., supra, 553 F.2d 837.
While these principles are reasonably clear, considerable legal uncertainty remains in cases in which the negligence of a shipowner combines with the negligence of an independent stevedore to cause injury to a longshoreman. Similarly, when harm is caused by an independent stevedore given complete control over the loading of a ship, it is unclear whether, everything being equal, a shipowner is liable for that harm even when he has knowledge of the dangerous condition caused by the stevedore. See Restatement (Second) of Torts, §§ 409-429; Lubrano v. Royal Netherlands Steamship Co., supra, 572 F.2d 364 at 367 (Moore, J., dissenting); Hickman v. Jugoslavenska Li-nijska Plovidba Rijeka, “Zvir”, 570 F.2d 449 (2d Cir. 1978).
Too strict a view of a shipowner’s liability in these situations would do much to diminish the salutary effects of the 1972 amendments by, in effect, making shipowners liable, once again, on what is akin to an unseaworthiness standard, but without recourse to contribution on the part of a negligent stevedore. Too lax a view would specifically contradict the congressional intention to make shipowners liable for their own negligence under the amended statute. See Report of the House Education and Labor Committee, H.R.Rep.No.92-1441, supra, at 4701-02. We are faced, then, with a difficult problem of line drawing which, at this stage in the development of the legal doctrine, is best undertaken on a case by case basis.
In the instant case, the trial court found Farrell liable on either of two alternative legal theories. First, it found that the ship’s crew placed cluster light wires on top of a patch of grease, thereby creating the dangerous condition which was the proximate cause of Canizzo’s injury. Second, it found that, in placing the cluster lights on the deck, the crew observed or should have observed the greasy patch, and was therefore on notice of the obviously unsafe condition aboard ship.
These findings rest on the trial court’s assessment of the credibility of plaintiff and of two of plaintiff’s witnesses, Mazze and Trovato, both of whom were fellow employees and friends of plaintiff and both of whom had unrelated injury claims pending. The court found both biased in plaintiff’s favor and rejected portions of the testimony of each, notably that of Trovato *686that a ship’s officer had observed the dangerous conditions at 1:00 or 2:00 p. m. The court did, however, credit the testimony that the grease, wire and cluster light wires existed in the area of the accident, that the grease was there at 1:30 or 2:00, and that the cluster lights had been placed on deck by the ship’s company.2
These conclusions are based primarily on the weighing of testimony by the trier who had the opportunity to observe witnesses Mazze and Trovato on the stand and listen to them under direct and cross-examination, and we find no basis for setting them aside. The existence of a substantial area of grease in a narrow passageway, which should have been known to the ship’s personnel, made more dangerous by the positioning by the ship’s personnel of the cluster lights and wires upon the greasy area supports the finding of negligence on the part of the ship and justifies the plaintiff’s judgment even under the new dispensation.
There is a strong presumption in favor of a trial court’s findings of fact if supported by substantial evidence. Pampillonia v. Concord Line, A/S, 536 F.2d 476 (2d Cir. 1976), Luigi Serra, Inc. v. SS Francesco C, 379 F.2d 540 (2d Cir. 1967) (maritime negligence). Such findings may be set aside only if clearly erroneous. Rule 52(a), Fed. R. Civ.P. Where no substantial evidence supports a factual determination, it is clearly erroneous, and properly set aside. United States ex rel. Paxos v. Rundle, 491 F.2d 447, 452 (3d Cir. 1974); Hodgson v. Fairmont Supply Co., 454 F.2d 490, 495 (4th Cir. 1972); Shenker v. United States, 322 F.2d 622, 624 (2d Cir.), cert. denied sub nom. American Stevedores, Inc. v. Shenker, 376 U.S. 907, 84 S.Ct. 659, 11 L.Ed.2d 606 (1963); Apache Powder Co. v. Ashton Co., 264 F.2d 417, 422 (9th Cir. 1959); Cleo Syrup Corp. v. Coca-Cola Co., 139 F.2d 416, 418 (8th Cir. 1943), cert. denied, 321 U.S. 781, 64 S. Ct. 638, 88 L.Ed. 1074 (1944); see 5A Moore’s Federal Practice If 52.03[1]; 9 Wright & Miller, Federal Practice & Procedure § 2585 n. 8.
Here the question is not so much whether the evidence supporting the findings on liability is substantial as whether it is credible. We are not convinced that the determination of credibility is clearly erroneous, although a contrary ruling might have been supportable.
The judgment establishing the ship’s liability must be affirmed.3
III.
The trial court found that because of Canizzo’s experience as a carpenter and his *687above-average intelligence, he was capable of earning $8500 per year. While we do not quarrel with the court’s estimation of Can-izzo’s intelligence, we are forced to conclude that it has taken an unfounded view of the employment potential of a 58-year-old, partially-disabled marine carpenter who has a history of heart trouble. While Canizzo may be capable of some employment, the record lacks any evidence as to its nature, availability or rate of compensation. The finding that he can earn $8500 per year until his retirement leaves this court “with the definite and firm conviction that a mistake has been committed” and that this finding is consequently clearly erroneous. United States v. U.S. Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 542, 92 L.Ed. 746 (1948); Schley v. CIR, 375 F.2d 747, 749-50 (2d Cir. 1967); Rule 52(a), Fed.R.Civ.P.
Accordingly, we must remand this case for redetermination of Canizzo’s damages.
The court’s dismissal of charges against Universal for failure of proof of Universal’s negligence, and its dismissal of charges against Holleran, as forbidden by the terms of 33 U.S.C. § 901 et seq., as amended, were correct.
The judgment of the district court is affirmed on the issue of liability, reversed on the issue of damages, and the case is remanded for further proceedings consistent with this opinion.
. Section 343A provides:
(1) A possessor of land is not liable to his invitees for physical harm caused to them by any activity or condition on the land whose danger is known or obvious to them, unless the possessor should anticipate the harm despite such knowledge or obviousness.
. While the testimony concerning the cluster lights is to some degree vague and inconsistent, there is some substantial basis for the court to conclude that it was more probable than not that the crew put them out. The longshoremen had often worked this ship and were familiar with its lighting. Trovato testified that “they” put two lights near every hatch and that the ship owns the cluster lights, Canizzo, that the crew takes care of them, Dennen (a Farrell witness by deposition) testified that they are owned by the ship, are ship’s gear, are stowed adjacent to the hatch, are made available and are available to where they are needed. Holler-an indicated that they were ship’s gear but usually hooked up by longshoremen. Davis, a ship superintendent for Universal, by deposition testified that the crew puts the cluster lights out and brings them to the hatch but that either the crew or Universal’s men plug them in. There is no indication that the cluster lights in question had yet been hooked up.
. Cox v. Flota Merchante Grancolombiana, S.A. was decided May 10, 1978, 577 F.2d 798, while this case was sub judice. Cox seems to us in conflict with at least Lubrano v. Royal Netherlands S.S. Co., 572 F.3d 364 (2d Cir. 1978), among the decisions in this circuit.
While each case must be determined on its own facts, the result in Cox cannot reasonably be reconciled with our result here by the differences in the factual situations, for the proof of ship’s negligence in Cox was at least comparable to that here. With all respect, however, we must disagree with the result in Cox. It appears to us to do what the Congress was unwilling to do, abolish the shipowner’s liability to the injured longshoreman in negligence as well as in unseaworthiness. As Judge Friendly points out, liability of the ship for such negligence as a greasy deck attributable to the ship’s company was specifically contemplated and thought to be preserved by the legislation.
Litigation in this troubled field would be tidier if the Congress had eliminated altogether the ship’s possible liability to longshoremen. There are, however, other considerations.
Benefits under the Longshoremen’s and Harbor Workers’ Act have been considerably increased. We cannot overlook the fact, how*687ever, that as is usual under workmen’s compensation schemes, they do not fully compensate for the loss suffered. If the ship, not a party to the employment contract, is absolved from liability for its own negligence, this uncompensated loss, which may be very great, is shifted from the negligent ship to the often innocent employee. The terms of the statute and the legislative history indicate to us that while Congress was willing to shift the burden of injury without fault to an improved compensation system for shore workers (who arguably never should have been classified with seamen anyway) it was not willing so to shift the burden of injury through the fault of the ship. This policy judgment we would leave to the Congress.