Exhibit 23.9

Consent of Independent Registered Public Accounting Firm

We consent to the reference to our firm under the caption “Experts” in the Registration Statement (on Form F-4) and related Prospectus of Compagnie Générale de Géophysique for the exchange offering of its outstanding 7¹/2% Senior Notes due 2015 and to the incorporation by reference therein of our report dated April 11, 2005, with respect to the consolidated financial statements of Compagnie Générale de Géophysique for the years ended December 31, 2004 and December 31, 2003 included in its Annual Report (on Form 20-F) for the year ended December 31, 2004 filed with the Securities and Exchange Commission.

Neuilly-sur-Seine and Paris La Défense, France
July 8, 2005

BARBIER FRINAULT & AUTRES ERNST & YOUNG AUDIT	MAZARS & GUERARD
/s/ Pascal Macioce	/s/ Philippe CASTAGNAC
Pascal MACIOCE	Philippe CASTAGNAC