
174 S.E.2d 846 (1970)
Marjorie KALE
v.
Fred DAUGHERTY and John Parnell.
No. 6926SC233.
Court of Appeals of North Carolina.
June 24, 1970.
*848 Ernest S. DeLaney, Jr., Charlotte, for plaintiff-appellant.
Carpenter, Golding, Crews & Meekins, by John G. Golding, Charlotte, for defendants-appellees.
PARKER, Judge.
Appellant's first assignment of error is directed to the court's action in excluding from evidence a small plate or plaque on which appeared the words:
"CautionOperate Blower At Least Five Minutes Before Starting Engine."
Appellant's counsel contends this plaque or one similar to it was on the dash beside the ventilator button on defendant Daugherty's boat at the time it was being operated by defendant Parnell on the occasion when plaintiff was injured. While there was testimony indicating that instructions of some nature concerning ventilation of the engine may have been affixed to the dash of the boat, no witness testified either that the exhibit offered had in fact been attached to the boat or that a plaque with similar language had been attached thereto. In the absence of any proper identification there was no error in excluding the exhibit from evidence. Stansbury, N.C. Evidence 2d, § 117, p. 264.
Appellant contends there was error in the judge's instruction to the jury that the defendant Daugherty "had no duty to the plaintiff in this case to repair the boat." For purpose of passing on this assignment of error, we do not find it necessary on this appeal to determine the exact extent of the duty to repair owed by the owner of a motorboat to socially invited guests on board. (For cases discussing the duty owed by the owner or operator of a motorboat to persons aboard, see Annotation, 63 A.L.R.2d 343, at page 355.) The quoted language in the court's charge, to which plaintiff excepted, appears only as the introductory phrase in a sentence in which the court added immediately thereafter the instruction: "[B]ut the Court instructs you that if he did undertake to repair it, that he would *849 owe a duty to the plaintiff to exercise reasonable care under the circumstances in the manner in which he undertook to repair the boat." The court had previously correctly instructed the jury as to the inherently dangerous nature of gasoline and the duty owed by one handling such a dangerous instrumentality to use due care commensurate with the known danger. Plaintiff alleged negligence on the part of Daugherty, not in failing to make repairs, but in the manner in which he attempted to make them. All of the evidence was to the effect that defendant Daugherty did in fact attempt to repair his boat. The court properly instructed the jury that defendant Daugherty owed to plaintiff the duty to exercise reasonable care in the manner in which he undertook to make the repairs. The jury could not have been misled to plaintiff's prejudice by the court's passing reference to absence of a duty which plaintiff had neither alleged nor sought to prove was breached by defendant Daugherty.
In the charge as a whole, considered contextually, the court correctly instructed the jury as to the duty of defendant Daugherty, the owner of the boat, to exercise due care, not only in making the repairs which he did attempt to make, but also as to his duty to make reasonable inspection of his boat and to warn plaintiff of any dangerous condition which such a reasonable inspection would have revealed. These were the only respects in which plaintiff alleged or sought to prove defendant Daugherty negligent. Appellant's assignments of error directed to the court's charge to the jury relative to the first issue are without merit and are overruled.
Appellant also assigns as error portions of the court's charge to the jury on the second issue relating to negligence on the part of defendant Parnell, the operator of the boat. In this connection appellant complains that the court placed an undue burden on her by instructing the jury in effect that they should find for the plaintiff on the second issue only if they should find that defendant Parnell knew or in the exercise of ordinary prudence under the circumstances should have known that the boat was in defective condition at the time he attempted to start the motor. These instructions, however, simply followed plaintiff's own theory, as alleged in her complaint, as to the manner in which defendant Parnell was negligent. Plaintiff did not allege, nor did the evidence tend to show, that the operator of the boat would have been negligent under all circumstances by attempting to start the motor without first activating the blower which ventilated the motor compartment. Her allegations were that the operator was negligent in that "[h]e knew or should have known that the boat and motor were in a defective condition and that gasoline could or might leak from the defective fuel line and accumulate under the hood covering the engine," and that "[n]evertheless, he attempted to start the engine without ventilating the engine compartment." There was evidence that while the boat was in motion ventilation for the engine compartment was normally accomplished by means of the air scoops provided for that purpose. All the evidence indicated that the boat had been in motion up until only a moment before the explosion. Plaintiff's theory as to defendant Parnell's negligence, at least insofar as disclosed by her allegations and evidence, was predicated on the assumption that a person of ordinary prudence, who either knew or in the exercise of reasonable care should have known of the possibility of leaking gasoline from the defective fuel line, would not have attempted to start the motor without first activating the blower fan or lifting the motor hood. Appellant cannot now successfully complain that the court charged the jury in conformity with her own theory of the case.
Finally, appellant contends there was error when the court instructed the *850 jury they should answer the first and second issues in favor of defendants if they should find there was an "unavoidable accident," as that term was defined by the court. "An unavoidable accident, as understood in the law of torts, can occur only in the absence of causal negligence." Baxley v. Cavenaugh, 243 N.C. 677, 92 S.E. 2d 68. Therefore, proper instructions on negligence, burden of proof, and proximate cause will usually render unnecessary an additional instruction on unavoidable accident. We do not find the instruction in the present case erroneous, however, since it was not unduly emphasized by the court and served only to call to the jury's attention the fact that they were under no necessity, under the facts shown by the evidence in this case, to find that someone was at fault. See Annotations, Unavoidable Accident Instruction, 65 A.L.R.2d 12.
Under instructions which we find free from reversible error the jury has found plaintiff's injuries were not caused by the negligence of either defendant. On the record before us, we find
No error.
MALLARD, C. J., and BRITT, J., concur.
