UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C.  20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. 1)

ORION MARINE GROUP
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(Name of Issuer)

Common Stock
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(Title of Class of Securities)

68628V308
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(CUSIP Number)

December 31, 2010
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(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

[X] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)

The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section
of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).

CUSIP No. 68628V308
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1.   NAME OF REPORTING PERSON
I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

Cortina Asset Management, LLC
56-2450074

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2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)    [ ]
(b)    [ ]

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3.   SEC USE ONLY

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4.   CITIZENSHIP OR PLACE OF ORGANIZATION

Wisconsin

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5.   SOLE VOTING POWER:  1,365,835

NUMBER OF      ------------------------------------------------------
SHARES         6.   SHARED VOTING POWER:  None
BENEFICIALLY
OWNED BY       ------------------------------------------------------
EACH           7.   SOLE DISPOSITIVE POWER:  1,522,694
REPORTING  
PERSON WITH    ------------------------------------------------------
8.   SHARED DISPOSITIVE POWER:  None

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9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,522,694

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10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES  [ ]

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11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.66

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12.  TYPE OF REPORTING PERSON

IA

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Item 1(a)   NAME OF ISSUER
Orion Marine Group    

(b)   ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES
12000 Aerospace Drive, Suite 300, Houston TX 77034

Item 2(a)   NAME OF PERSONS FILING
Cortina Asset Management, LLC

(b)   ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE
825 N Jefferson Street, Suite 400, Milwaukee, Wisconsin  53202

(c)   CITIZENSHIP
Cortina is a Wisconsin limited liability company

(d)   TITLE OF CLASS OF SECURITIES
Common Stock

(e)   CUSIP NUMBER
68628V308

Item 3.     Type of Person:

(e)   [X]  Cortina is an Investment Adviser registered under section 203
of the Investment Advisors Act of 1940

Item 4.     OWNERSHIP

Ownership (as December 31, 2010):

(a)   Amount owned "beneficially" within the meaning of rule 13d-3:
1,522,694

(b)   Percent of class:

5.66 (based on 26,899,679 shares outstanding as of November 1, 2010.)

(c)   Number of shares as to which such person has:

(i)    Sole power to vote or to direct the vote  

1,365,835

(ii)   Shared power to vote or direct the vote

None

(iii)  Sole power to dispose or to direct the 
disposition of

1,522,694

(iv)   Shared power to dispose or to direct the
disposition of

None

Item 5.     OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

Not Applicable

Item 6.     OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

Not Applicable

Item 7.     IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING
COMPANY OR CONTROL PERSON

Not Applicable

Item 8.     IDENTIFICATION AND CLASSIFICAITON OF MEMBERS OF THE GROUP

Not Applicable

Item 9.     NOTICE OF DISSOLUTION OF GROUP

Not Applicable

Item 10.    CERTIFICATION

By signing below I certify that, to the best of my knowledge and belief, the
securities referred to above were acquired and are held in the ordinary course
of business and were not acquired and are not held for the purpose or with the
effect of changing or influencing the control of the issuer of the securities
and were not acquired and are not held in connection with or as a participant
in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

January 25, 2011
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Date

/s/LORI K. HOCH
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Signature

Lori K. Hoch
Chief Operating Officer and 
Chief Compliance Officer
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Name/Title