13D Filing: Blue Mountain Capital and Ocean Rig UDW Inc.

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CUSIP No. G66964118

Item 1. Security of the Issuer.

This Schedule 13D
relates to the shares of Common Stock, par value $0.01 per share (the Common Stock), of Ocean Rig UDW Inc., a Cayman Islands corporation (the Issuer). The Issuers principal executive office is located at
c/o Ocean Rig Cayman Management Services SEZC Limited, 3^rd Floor Flagship Building, Harbour Drive, Grand Cayman, Cayman Islands.

Item 2. Identity and Background.

(a-c) This
Statement is being filed by the following beneficial owners of Common Stock (each, a Reporting Person):

(i)

Blue Mountain Credit Alternatives Master Fund L.P., a Cayman Islands exempted limited partnership (BMCA), with respect to the Common Stock directly owned by it;

(ii)

Blue Mountain CA Master Fund GP, Ltd., a Cayman Islands exempted limited company (BMCA GP), with respect to the Common Stock directly owned by BMCA;

(iii)

Blue Mountain Credit GP, LLC, a Delaware limited liability company (BMC GP), which serves as the sole owner of BMCA GP, with respect to the Common Stock directly owned by BMCA;

(iv)

BlueMountain Foinaven Master Fund L.P., a Cayman Islands exempted limited partnership (BMF), with respect to the Common Stock directly owned by it;

(v)

BlueMountain Foinaven GP, LLC, a Delaware limited liability company (BMF GP), with respect to the Common Stock directly owned by BMF;

(vi)

BlueMountain Guadalupe Peak Fund L.P., a Delaware limited partnership (BMGP), with respect to the Common Stock directly owned by it;

(vii)

BlueMountain Long/Short Credit GP, LLC, a Delaware limited liability company (BMGP GP), with respect to the Common Stock directly owned by BMGP;

(viii)

BlueMountain Montenvers Master Fund SCA SICAV-SIF, an investment company with variable share capital organized as a specialized investment fund in the form of a corporate partnership limited by shares under the laws of Luxembourg (BMM), with respect to the Common Stock directly owned by it;

(ix)

BlueMountain Montenvers GP S.à r.l., a private limited company incorporated under the laws of Luxembourg (BMM GP), with respect to the Common Stock directly owned by BMM;

(x)

BlueMountain Summit Trading L.P., a Delaware limited partnership (BMST), with respect to the Common Stock directly owned by it;

(xi)

BlueMountain Summit Opportunities GP II, LLC, a Delaware limited liability company (BMST GP), with respect to the Common Stock directly owned by BMST;

(xii)

BlueMountain Kicking Horse Fund L.P., a Cayman Islands limited partnership (BMKH), with respect to the Common Stock directly owned by it;

(xiii)

BlueMountain Kicking Horse Fund GP, LLC, a Delaware limited liability company (BMKH GP and, together with BMC GP, BMF GP, BMGP GP and BMST GP, the General Partners), with respect to the Common Stock directly owned by BMKH;

(xiv)

BlueMountain Timberline Ltd., a Cayman Islands exempted limited company (BMT and, together with BMCA, BMF, BMGP, BMM, BMST and BMKH, the BlueMountain Funds), with respect to the Common Stock directly owned by it;

(xv)

BlueMountain GP Holdings, LLC, a Delaware limited liability company (GP Holdings), which serves as the sole owner of each of the General Partners, with respect to the Common Stock directly owned by each of BMCA, BMF, BMGP, BMST and BMKH; and

(xvi)

BlueMountain Capital Management, LLC, a Delaware limited liability company (BMCM or the Investment Manager), which serves as the sole owner of BMM GP and investment manager to, and makes investment decisions on behalf of, the BlueMountain Funds, with respect to the Common Stock directly owned by the BlueMountain Funds and BMCM.