EXHIBIT 21

List of Subsidiaries

Aberuchill Ltd.

Atlantic Maritime Services, Inc.

British American Offshore Limited

LeTourneau Technologies, Inc.

LeTourneau Technologies America, Inc.

LeTourneau Technologies Asia Pte. Ltd.

LeTourneau Technologies (Australia) Pty. Ltd.

LeTourneau Technologies Brazil, Inc.

LeTourneau Technologies Canada Ltd.

LeTourneau Technologies Comércio de Equipamentos Industriais do Brasil Ltda.

LeTourneau Technologies (Dalian) Co., Ltd.

LeTourneau Technologies Drilling Systems, Inc.

LeTourneau Technologies International, Inc.

LeTourneau Technologies Middle East FZE

LeTourneau Technologies South America, Inc.

RCI Drilling International, Inc.

RCI International, Inc.

RDC Arabia Drilling, Inc.

RDC Drilling, Ltd.

RDC Drilling International, Inc.

RDC International, Inc.

RDC Marine, Inc.

RDC Qatar, Inc.

Rowan 240C#3, Inc.

Rowan 240C#4, Inc.

Rowan Angola Limitada

Rowan Canada Limited

Rowan Drilling & Aviation (Netherlands) B.V.

Rowan Drilling Company, Inc.

Rowan Drilling (U.K.) Ltd.

Rowan Finance Company

Rowan International, Inc.

Rowan J.P. Bussell, Inc.

Rowan Marine Drilling, Inc.

Rowan Marine Services, Inc.

Rowan Middle East, Inc.

Rowan North Sea, Inc.

Rowan Petroleum, Inc.

Rowan Ralph Coffman, Inc.

Rowandrill, Inc.

Rowan S116E#1, Inc.

Rowan S116E#2, Inc.

Rowan S116E#3, Inc.

Rowan S116E#4, Inc.