EXHIBIT 11 TIDEWATER INC. COMPUTATION OF EARNINGS AND SHARES USED IN ARRIVING AT PRIMARY AND FULLY-DILUTED EARNINGS PER SHARE FOR THE QUARTER AND NINE-MONTH PERIOD ENDED DECEMBER 31, 1996 Quarter Ended Nine Months Ended December 31, 1996 December 31, 1996 ----------------- ----------------- Net earnings (in thousands) $ 43,170 $ 100,492 ============= ============ Computation of weighted average number of shares outstanding: - ------------------------ Issued: 61,400,819 Weighted average shares outstanding 61,951,401 61,970,101 Plus incremental shares applicable to stock options 714,639 670,629 ------------- ------------ Weighted average common shares and equivalents 62,666,040 62,640,730 ============= ============ Primary and fully diluted earnings per common share $ .68 $ 1.60 ============= ============ 1