The correct material elements of the DUI offense, and the proper standard of proof: "In order to convict Vliet of DUI, as prohibited by HRS 291-4 (a) (1), the prosecution was required to prove beyond a reasonable doubt that (1) Vliet (2) operated or assumed actual physical control of the operation of any vehicle while (3) under the influence of intoxicating liquor in an amount sufficient to impair his normal mental faculties or ability to care for himself and guard against casualty." State v. Vliet, 91 Haw. 288 at 289, 292, 983 P.2d 189, 193 (1999). As trier of fact, the court "'may draw all reasonable and legitimate inferences and deductions from the evidence adduced . . ., and findings of the trial court will not be disturbed unless clearly erroneous." State v. Nelson, 69 Haw. 461, 469, 748 P.2d 365, 370 (1987). "A finding of fact is clearly erroneous when: (1) the record lacks substantial evidence to support the finding, or (2) despite substantial evidence in support of the finding, the appellate court is nonetheless left with a definite and firm conviction that a mistake has been made." State v. Okumura, 78 Haw. 383, 392, 894 P.2d 80, 89 (1995). Substantial evidence as to every essential element of the crime charged is required in order to support a conviction. Substantial evidence is "credible evidence which is of sufficient quality and probative value to enable a man of reasonable caution to reach a conclusion. It is evidence which a reasonable mind might accept as adequate to support such a conclusion. and whether substantial evidence exists to support a conviction is to be determined by an appellate court upon review of the evidence adduced in the light most favorable to the prosecution." State v. Naeole, 62 Haw. 563, 565, 617 P.2d 820, 823 (1980) "During a criminal bench trial, trial courts are regularly called upon to consider the credibility of witnesses and weigh the evidence. We must give due deference to their ability to separate a determination of credibility and weighing of the evidence from the application of the proper standard of proof -- beyond a reasonable doubt." State v. Aplaca, 74 Haw. 54, 65, 837 P.2d 1298, 1304-05 (1992). In State v. Bush, 58 Haw. 340, 569 P.2d 349 (1977), the supreme court held that a case of circumstantial evidence does not require, in addition to a general instruction on "proof beyond a reasonable doubt" applicable to both direct and circumstantial evidence, instruction that the circumstantial evidence be "inconsistent with every reasonable hypothesis of innocence" or "foreclose the hypothesis of innocence." Id. at 344, 569 P.2d at 352.