Exhibit 21.1

ATWOOD OCEANICS, INC.

SUBSIDIARY AND AFFILIATED COMPANIES, STATE OR

JURISDICTION OF INCORPORATION AND OWNERSHIP PERCENTAGE

Alpha Aurora Company	Cayman Islands	100%
Alpha Falcon Company	Cayman Islands	100%
Alpha Falcon Drilling Company	Cayman Islands	100%
Alpha Leasing Drilling Limited	Mauritius	100%
Alpha Offshore Drilling (Cambodia) Ltd.	Cambodia	100%
Alpha Offshore Drilling (S) Pte. Ltd.	Singapore	100%
Alpha Offshore Drilling Services Company	Cayman Islands	100%
Alpha Offshore Drilling Services Company – Free Zone	Egypt	100%
Alpha Offshore Drilling Services Company – Ghana	Ghana	100%
ATW Management, Inc.	Delaware	100%
Atwood Deep Seas, Ltd. (Partnership)	Texas	100%
Atwood Drilling, Inc.	Delaware	100%
Atwood Hunter Co.	Delaware	100%
Atwood Management, Inc.	Delaware	100%
Atwood Oceanics Australia Pty. Ltd.	Australia	100%
Atwood Oceanics Australia Superannuation Fund Pty. Ltd.	Australia	100%
Atwood Oceanics Drilling Pty. Ltd.	Australia	100%
Atwood Oceanics International Limited	Cayman Islands	100%
Atwood Oceanics Leasing Ltd.	Malaysia	100%
Atwood Oceanics (M) Sdn. Bhd.	Malaysia	100%
Atwood Oceanics Malta Ltd	Malta	100%
Atwood Oceanics Management, L.P. (Partnership)	Delaware	100%
Atwood Oceanics (NZ) Limited	New Zealand	100%
Atwood Oceanics Pacific Limited	Cayman Islands	100%
Atwood Oceanics Platforms Pty. Ltd.	Australia	100%
Atwood Oceanics Services Pty. Ltd.	Australia	100%
Atwood Oceanics West Tuna Pty. Ltd.	Australia	100%
Atwood Offshore Drilling Ltd.	Hong Kong	100%
Aurora Offshore Services GmbH	Germany	100%
Clearways Offshore Drilling Sdn. Bhd.	Malaysia	49%
Drillquest (M) Sdn. Bhd.	Malaysia	100%

ATWOOD OCEANICS, INC.

SUBSIDIARY AND AFFILIATED COMPANIES, STATE OR

JURISDICTION OF INCORPORATION AND OWNERSHIP PERCENTAGE

Drillquest International Offshore Drilling Services Company	Cayman Islands	100%
Drillquest Offshore Company	Cayman Islands	100%
Pacific Offshore Labor Company	Cayman Islands	100%

PT Alpha Offshore Drilling	Indonesia	100%
PT Pentawood Offshore Drilling	Indonesia	80%
Swiftdrill, Inc.	Cayman Islands	100%
Swiftdrill Malta (Partnership)	Malta	100%
Swiftdrill Nigeria Limited	Nigeria	60%
Swiftdrill Offshore Drilling Services Company	Cayman Islands	100%