Ocean Rig UDW F-4 Registration of securities (foreign)

Exhibit 99.1

LETTER OF TRANSMITTAL

This Letter of Transmittal relates to the offer to exchange, commencing on          , 2011, an aggregate of 25,667,600 new common shares of Ocean Rig UDW Inc. (the “Company”) that have been registered for exchange, or the Exchange Shares, for an equivalent number of common shares, previously sold in a private offering, or the Original Shares, (the “Exchange Offer”) pursuant to the Prospectus dated          , 2011 (the “Prospectus”).

Properly completed and signed letter of transmittals may be faxed, sent by post or delivered to the Norwegian Exchange Agent:

Nordea Bank Norge ASA
Securities Services — Issuer Services
Essendropsgate 7, P.O. Box 1166 Sentrum
N-0107 Oslo, Norway
Fax: (+47) 22 48 63 49
Tel: (+47) 22 48 62 62
E-mail: issuerservices@nordea.com

The Company’s share register shows on          , 2011:

VPS Account: Number of Original Shares: Rights holder registered:

The undersigned hereby instructs the agents of the Company to cause the deposit of the Exchange Shares to the Depository Trust Company (DTC) Participant Account No. set forth below and has indicated below the undersigned’s underlying customer account number.

Depository Trust Company
(DTC) Participant Account
No. Customer Account No.

EXPIRATION DATE:  The Exchange Offer expires at 5:00 p.m., New York City time (11:00 p.m. Oslo time), on          , 2011, unless extended as described in the Prospectus (as extended, the “Expiration Date”). Shareholders who own shares in the Company allocated to more than one VPS-account will receive one letter of transmittal for each account. All letters of transmittals must be completed, signed and returned within the deadline.

Under the terms of the Exchange Offer, you will not be able to sell, pledge or otherwise encumber or transfer to another VPS-account the Original Shares that are covered by this letter of transmittal. The Company will settle all directly attributable VPS-transaction costs that may occur as a direct consequence of your acceptance of the Exchange Offer.

The Exchange Offer cannot be accepted in any jurisdictions in which the making of the Exchange Offer or acceptance thereof would not be in compliance with the laws of such jurisdictions.

The Company reserves the right to transfer or assign, in whole at any time or in part from time to time, to one or more of its affiliates the right to exchange all or any portion of the Original Shares tendered pursuant to the Exchange Offer, but any such transfer or assignment will not relieve the Company of its obligations under the Exchange Offer or prejudice the undersigned’s rights to exchange the Original Shares validly tendered and accepted for exchange pursuant to the Exchange Offer.

The Exchange Offer is subject to certain conditions as set forth in the Prospectus under the caption “The Exchange Offer — Conditions of the Exchange Offer.” As a result of these conditions (which may be waived, in whole or in part, by the Company), as more particularly set forth in the Prospectus, the Company may not be required to exchange any of the Original Shares tendered hereby and, in such event, the Original Shares not exchanged will be returned to the undersigned at the address shown above, promptly following the expiration or termination of the Exchange Offer. In addition, the Company may amend the Exchange Offer at any time prior to the Expiration Date if any of the conditions set forth under

“The Exchange Offer — Conditions of the Exchange Offer” occur. In the event of any material change in the Exchange Offer, including the waiver of a material condition of the Exchange Offer, the offer period will be extended for at least five business days following notice of the material change.

Tenders of Original Shares pursuant to any one of the procedures described in the Prospectus will, upon the Company’s acceptance for exchange of such tendered Original Shares, constitute a binding agreement between the undersigned and the Company upon the terms and subject to the conditions of the Exchange Offer. The Under circumstances set forth in the Prospectus, the Company may not be required to accept for exchange any of the Original Shares.

To the Company and the Norwegian Exchange Agent:

1.	I/we irrevocably accept the offer to exchange all of my/our Original Shares for Exchange Shares in accordance with the terms and conditions set out in the Prospectus and this letter of transmittal. (which together, as amended, supplemented or modified from time to time, constitute the “Exchange Offer”).
2.	I/we accept the Exchange Offer for all of my/our Original Shares. The acceptance comprises, in addition to the Original Shares I/we have registered on the VPS-account stated at the top of this letter of transmittal, any Original Shares I/we have or will acquire and which are credited to the above-mentioned VPS-account until the Original Shares are debited my/our VPS-account.
3.	The Norwegian Exchange Agent is irrevocably authorized, subject to the withdrawal rights described below, to block the Original Shares on the above-mentioned VPS-account in favor of the Norwegian Exchange Agent on behalf of the Company.
4.	The Norwegian Exchange Agent is irrevocably authorized, subject to the withdrawal rights described below, to tender the Original Shares to the Company against exchange of the Exchange Shares. Upon the terms and subject to the conditions of the Exchange Offer (and if the Exchange Offer is extended or amended, the terms of any such extension or amendment), effective upon acceptance for the Original Shares tendered herewith, the undersigned (i) will have irrevocably sold, assigned and transferred to the Company all right, title and interest in, to and under all of the Original Shares tendered for exchange hereby; and (ii) appoints the Norwegian Exchange Agent as the true and lawful agent and attorney-in-fact (with full knowledge that the Norwegian Exchange Agent also acts as agent for the Company) of such holder of Original Shares with respect to such Original Shares, with full power of substitution, to (x) transfer ownership of such Original Shares on the account books maintained by Nordea Bank Norge ASA as the Company’s Transfer Agent and Registrar (the “Transfer Agent”) (together with all accompanying evidences of transfer and authenticity), (y) take any action necessary to transfer such Original Shares to the Company; and (z) receive all benefits and otherwise exercise all rights and incidents of ownership with respect to such Original Shares, all in accordance with the terms of the Exchange Offer. The power of attorney granted in this paragraph shall be deemed to be irrevocable and coupled with an interest.
5.	The Original Shares will be transferred free of any encumbrances or other third-party rights whatsoever and with all shareholder rights attached to them. I/we acknowledge that this acceptance will only be regarded as valid if any third party with registered encumbrances or other third-party rights over the above-mentioned VPS account has approved by signing this letter of transmittal that the Original Shares may be exchanged free of any encumbrances or other third-party rights with Exchange Shares. The undersigned represents and warrants that it has full power and authority to tender, exchange, assign and transfer the Original Shares and to acquire Exchange Shares issuable upon the exchange of such tendered Original Shares, and that, when the same are accepted for exchange, the Company will acquire good and unencumbered title to the tendered Original Shares, free and clear of all liens, restrictions, charges and encumbrances and not subject to any adverse claim. The undersigned also warrants that it will, upon request, execute and deliver any additional documents deemed by the Exchange Agents or the Company to be necessary or desirable to complete the exchange, assignment and transfer of the tendered Original Shares or transfer ownership of such Original Shares on the account books maintained by the Transfer Agent.
6.	By tendering Original Shares and executing this Letter of Transmittal, the undersigned represents that (1) the Exchange Shares acquired pursuant to the Exchange Offer will be, and the Original Shares being tendered were, acquired in the ordinary course of business of the undersigned, (2) the undersigned is not engaging in and does not intend to engage in a distribution of the Exchange Shares, (3) the undersigned does not have an arrangement or understanding with any

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person to participate in the distribution of such Exchange Shares, (4) the undersigned is not an “affiliate” of the Company within the meaning of Rule 405 under the Securities Act of 1933, as amended, and (5) the undersigned is not acting on behalf of any person who could not truthfully make the foregoing representations. If the undersigned is a broker-dealer that will receive Exchange Shares for its own account in exchange for Original Shares that were acquired as a result of market-making activities or other trading activities, it acknowledges that it will deliver a Prospectus meeting the requirements of the Securities Act of 1933, as amended, in connection with any resale of such Exchange Shares to the extent required by applicable law or regulation or SEC pronouncement. By acknowledging that it will deliver and by delivering a Prospectus meeting the requirements of the Securities Act of 1933, as amended, in connection with any resale of such Exchange Shares, the undersigned is not deemed to admit that it is an “underwriter” within the meaning of the Securities Act of 1933, as amended.

7.	Any holder of Original Shares using the Exchange Offer to participate in a distribution of the Exchange Shares (i) cannot rely on the position of the staff of the Securities and Exchange Commission enunciated in its interpretive letter with respect to Exxon Capital Holdings Corporation (available May 13, 1988) or similar interpretive letters and (ii) must comply with the registration and Prospectus delivery requirements of the Securities Act of 1933, as amended, in connection with a secondary resale transaction.
8.	All authority herein conferred or agreed to be conferred shall survive the death or incapacity of the undersigned and every obligation of the undersigned hereunder shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned. Tendered Original Shares may be withdrawn at any time prior to the Expiration Date in accordance with the terms of this Letter of Transmittal. You may withdraw your tender of Original Shares at any time prior to the Expiration Date.
9.	For a withdrawal of tendered Original Shares to be effective, a written notice of withdrawal must be received by the Norwegian Exchange Agent, at its address set forth above prior to the Expiration Date. Any such notice of withdrawal must: (i) specify the name of the person who tendered the Original Shares to be withdrawn; (ii) identify the Original Shares to be withdrawn; and (iii) be signed by the holder of such Original Shares in the same manner as the original signature on the letter of transmittal by which such Original Shares were tendered or be accompanied by (i) documents of transfer sufficient to have our Transfer Agent register the transfer of the Original Shares into the name of the person withdrawing such Original Shares, and (ii) a properly completed irrevocable proxy authorizing such person to effect such withdrawal on behalf of such holder.

10.  All questions as to the validity, form and eligibility, including time of receipt, of such notices will be determined by the Company, and our determination shall be final and binding on all parties. Any Original Shares withdrawn will be considered not to have been validly tendered for exchange for the purposes of the Exchange Offer. Any Original Shares that have been tendered for exchange but that are not exchanged for any reason will be returned to you without cost promptly after withdrawal, rejection of tender or termination of the Exchange Offer. Properly withdrawn Original Shares may be re-tendered at any time on or prior to the Expiration Date.

Place Date Binding signature* Telephone

*	If signed by power of attorney, the power of attorney (and with respect to companies, Certificate of Registration or similar documentation) shall be enclosed.
*	If signed by a person with signatory right, Certificate of Registration or similar documentation shall be enclosed.

Rights holder:

If there is a registered rights holder on the VPS account, this will be marked with a YES in the right-hand box on the letter of transmittal. As rights holder(s), the undersigned consents to the transaction being carried out on the above-mentioned terms and that the shares are transferred to the Company free of any liens or encumbrances.

Place Date Rights holder’s binding signature*

*	If signed by power of attorney, the power of attorney (and with respect to companies, Certificate of Registration or similar documentation) shall be enclosed.
*	If signed by a person with signatory right, Certificate of Registration or similar documentation shall be enclosed.
*	If more than one rights holder is registered, each rights holder must sign.

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