1 EXHIBIT 11.1 DIAMOND OFFSHORE DRILLING, INC. STATEMENT RE COMPUTATION OF PER SHARE EARNINGS (IN THOUSANDS, EXCEPT PER SHARE DATA) THREE MONTHS ENDED SEPTEMBER 30, ------------------------------------------------------------------------------ 1998 1997 -------------------------------------- ------------------------------------- WEIGHTED WEIGHTED (1) AVERAGE AVERAGE INCOME SHARES PER SHARE INCOME SHARES PER SHARE (NUMERATOR) (DENOMINATOR) AMOUNT (NUMERATOR) (DENOMINATOR) AMOUNT -------------------------------------- ------------------------------------- BASIC EPS Net income.............................. $ 108,702 137,652 $ 0.79 $ 77,831 139,303 $ 0.56 EFFECT OF DILUTIVE POTENTIAL SHARES Convertible notes issued 2/4/97 ........ 2,350 9,876 2,306 9,876 -------------------------------------- ------------------------------------- DILUTED EPS Net income + assumed conversions ....... $ 111,052 147,528 $ 0.75 $ 80,137 149,179 $ 0.54 ====================================== ===================================== NINE MONTHS ENDED SEPTEMBER 30, ----------------------------------------------------------------------------- 1998 1997 -------------------------------------- ------------------------------------- WEIGHTED WEIGHTED (1) AVERAGE AVERAGE INCOME SHARES PER SHARE INCOME SHARES PER SHARE (NUMERATOR) (DENOMINATOR) AMOUNT (NUMERATOR) (DENOMINATOR) AMOUNT -------------------------------------- ------------------------------------- BASIC EPS Net income.............................. $ 301,089 138,762 $ 2.17 $ 199,295 138,308 $ 1.44 EFFECT OF DILUTIVE POTENTIAL SHARES Convertible notes issued 2/4/97 ........ 7,305 9,876 4,418 8,610 -------------------------------------- ------------------------------------- DILUTED EPS Net income + assumed conversions ....... $ 308,394 148,638 $ 2.07 $ 203,713 146,918 $ 1.39 ====================================== ===================================== - ---------- (1) Weighted average shares outstanding have been restated to include the retroactive effect of the July 1997 two-for-one stock split in the form of a stock dividend.