EXHIBIT 22.1 SUBSIDIARY COMPANIES AND STATE OR JURISDICTION OF INCORPORATION Atwood Oceanics Drilling Company Texas 100% Swiftdrill, Inc. Texas 100% Eagle Oceanics, Inc. Texas 100% Hunter Co. Texas 100% Falcon Co. Texas 100% Atwood Deep Seas, Ltd. Texas Limited 50% Partnership Atwood Falcon I, Ltd. Texas Limited 50% Partnership Atwood Oceanics Australia Pty. Ltd. Australia 100% Atwood Oceanics Services Pty. Ltd. Australia 100% Atwood Oceanics Platforms Pty. Ltd. Australia 100% Deep Seas Drilling Pty. Ltd. Australia 100% Atwood Oceanics Drilling Pty. Ltd. Australia 100% Clearways Sdn. Bhd. Malaysia 30% Atwood Oceanics (M) Sdn. Bhd. Malaysia 100% Clearways Offshore Development Drilling Sdn. Bhd. Malaysia 30% Atwood Oceanics International, S.A. Panama 100% Atwood Oceanics Pacific Limited Cayman Islands, 100% B.W.I. Aurora Offshore Services GmbH West Germany 100% All Oceans Drilling B.V. Netherlands 100% Atwood Oceanics Singapore Pte. Ltd. Singapore 100% Swiftdrill Nigeria Limited Nigeria 60% P. T. Pentawood Offshore Drilling Indonesia 80% Isobuild Sdn. Bhd. Malaysia 90% Vista Mayang Sdn. Bhd. Malaysia 90% Atwood Oceanics West Tuna Pty. Ltd. Australia 50% Atwood Oceanics (NZ) Ltd. New Zealand 100%