UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report Pursuant to Section 13 or 15(d) of

the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 7, 2017

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

On August 7, 2017, West Marine, Inc. issued a press release announcing its financial results for the 13-week period (second quarter) ended July 1, 2017 and for the 26-week period ended July 1, 2017. A copy of this press release is attached hereto as Exhibit 99.1.

In addition to disclosing financial results that are determined in accordance with accounting principles, generally accepted in the United States (“GAAP”), the press release discloses EBITDA and earnings per share adjusted for certain one-time events that occurred during the second quarter.

We believe EBITDA provides a helpful picture of the operating performance of the business. EBITDA is calculated as net income (loss) plus interest expense, depreciation and amortization, and income tax expense. EBITDA is not a presentation made in accordance with GAAP, is not a measure of financial performance or condition, liquidity or profitability, and should not be considered as alternatives to (1) net income, operating income or any other performance measures determined in accordance with GAAP or (2) operating cash flows determined in accordance with GAAP. Additionally, EBITDA is not intended to be a measure of free cash flow for management’s discretionary use, as it does not consider certain cash requirements such as interest payments, tax payments, debt service requirements and replacements of fixed assets. By eliminating interest, income taxes, depreciation and amortization, we believe the result is a useful measure across time in evaluating our fundamental core operating performance. We also believe that EBITDA provides a clearer picture of operating performance of the business, given the significant investments we are making in the growth of the business, by eliminating the effects of depreciation and interest expense.

Management believes that the presentation of EBITDA is useful to investors because these measures are frequently used by securities analysts, investors and other interested parties in the evaluation of the operating performance of companies in our industry and industries similar to ours. Management also uses EBITDA to evaluate our operations. However, as indicated, EBITDA does not include interest expense on borrowed money, the payment of income taxes, amortization of our definite-lived intangible assets, or depreciation expense on our capital assets, which are necessary elements of our operations. Since EBITDA does not account for these and other expenses, its utility as a measure of our operating performance has limitations. Due to these limitations, management does not view EBITDA in isolation, but also uses other measurements, such as net income and revenues to measure operating performance.

We believe adjusted earnings per share provides a better understanding of the fundamental performance of the business because the events being adjusted are not anticipated to be recurring in the normal course of our core operations. Adjusted earnings per share is calculated by adjusting for expenses associated with a previously-announced proposed merger transaction, a currency translation adjustment charge related to cessation of our Canadian operations and a credit from a supplier for prior year over-billing. Adjusted earnings per share should be considered as a supplement to, and not as a substitute for, or superior to, financial measures calculated in accordance with GAAP.

Our presentation of EBITDA and adjusted earnings per share has limitations as analytical tools, and should not be considered in isolation or as a substitute for analysis of our results as reported under GAAP. Because not all companies use identical calculations, the presentation of EBITDA may not be, and adjusted earnings per share most likely will not be, comparable to other similarly titled measures of other companies.

Management has reconciled these non-GAAP financial measures to the most directly comparable GAAP financial measures in the tables included in the press release furnished as Exhibit 99.1 to this report. EBITDA and adjusted earnings per share should be considered as supplements to, and not as substitutes for, or superior to, financial measures calculated in accordance with GAAP.

The information furnished pursuant to Item 2.02 and Exhibit 99.1 of this report shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, except if we specifically incorporate it by reference into a filing under the Securities Act of 1933, as amended, or the Exchange Act.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.