The nutritional status of 16 male, land-based U.S. Navy divers was assessed to collect baseline information for a cold water dive series. Diet records, blood samples, and 24-h urine collections were obtained and analyzed. The divers were deriving 17 +/- 1%, 40 +/- 2%, 32 +/- 2% of their calories from protein, carbohydrate, and fat, respectively. The remaining calories were furnished by alcohol (11 +/- 2%), an amount within the American Heart Association's guidelines. Crude fiber intake was low (3.7 +/- 0.4 g/d) whereas cholesterol (507 +/- 101 mg/d) and sodium intakes (4462 +/- 599 mg/d) were high. Mean intakes of vitamin B6 and folacin were below the Military Recommended Dietary Allowances. Mean blood concentrations and urinary excretion of minerals were normal but urinary sodium excretion was high. Results indicate that the divers' intakes of sodium and cholesterol were high, whereas intakes of complex carbohydrate and crude fiber were low. Whether these dietary patterns are suitable for extended dives, especially in cold water, remains to be determined.