Note 1 - General Information

6 Months Ended

Jun. 30, 2013

Disclosure Text Block [Abstract]

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

(1)           GENERAL INFORMATION

Organization and Nature of Operations

The condensed consolidated financial statements of GulfMark Offshore, Inc. and its subsidiaries included herein have been prepared by us without audit, pursuant to the rules and regulations of the Securities and Exchange Commission, or SEC. Unless otherwise indicated, references to “we”, “us”, “our” and the “Company” refer collectively to GulfMark Offshore, Inc. and its subsidiaries and predecessors. Certain information relating to our organization and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles, or U.S. GAAP, has been condensed or omitted in this Form 10-Q pursuant to such rules and regulations. However, we believe that the disclosures herein are adequate to make the information presented not misleading. The consolidated balance sheet as of December 31, 2012, has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. It is recommended that these financial statements be read in conjunction with our consolidated financial statements and notes thereto included in our Form 10-K for the year ended December 31, 2012.

In the opinion of management, all adjustments, which include reclassification and normal recurring adjustments necessary to present fairly the unaudited condensed consolidated financial statements for the periods indicated have been made. All significant intercompany accounts have been eliminated. Certain reclassifications of previously reported information may be made to conform with current year presentation.

We provide offshore marine support and transportation services primarily to companies involved in the offshore exploration and production of oil and natural gas. Our vessels transport materials, supplies and personnel to offshore facilities, as well as move and position drilling structures. The majority of our operations are conducted in the North Sea, offshore Southeast Asia and the Americas. We also operate our vessels in other regions to meet our customers’ requirements.

Earnings Per Share

Basic Earnings Per Share, or EPS, is computed by dividing net income (loss) by the weighted average number of shares of Class A Common Stock outstanding during the period. Diluted EPS is computed using the treasury stock method for Class A Common Stock equivalents. The reconciliation between basic and diluted earnings per share from income or loss attributable to Class A Common Stock stockholders, including allocation to participating securities, is as follows:

	Three Months Ended June 30,					Six Months Ended June 30,
	2013		2012			2013		2012
Income:	(In thousands, except per share amounts)					(In thousands, except per share amounts)
Net income attributable to common stockholders	$	9,856	$	14,064		$	12,727	$	11,155
Undistributed income allocated to participating securities		-		(28	)		-		(46	)
Basic		9,856		14,036			12,727		11,109
Undistributed income allocated to participating securities		-		28			-		46
Undistributed income reallocated to participating securities		-		(28	)		-		(46	)
Diluted	$	9,856	$	14,036		$	12,727	$	11,109
Shares:
Basic
Weighted-average common shares outstanding		26,120		26,243			26,082		26,120
Dilutive effect of stock options and restricted stock awards		8		18			7		36
Diluted		26,128		26,261			26,089		26,155
Income per common share:
Basic	$	0.38	$	0.53		$	0.49	$	0.43
Diluted	$	0.38	$	0.53		$	0.49	$	0.42