The time charter rate for the four ships, including Rena, is US$16,580 per day, according to a presentation to investors in June of this year.
Based on a vessel acquisition price of US$11.25 million per ship and estimate of earnings before interest, tax, depreciation and amortisation of US$3.7 million a year, the company calculated a yield on Rena of 32 per cent.
Costamare says in documents filed to the Securities and Exchange Commission that the container shipping industry experienced weakness from the middle of 2008 through the first half of 2010.
Costamare told investors that its management team had "overcome the worst container shipping crisis in history" and the company was now uniquely positioned for growth.
The key to making superior returns was purchasing ships at the right time.
The market for container ship owners improved as global fleet capacity and order books for new ships fell and charter rates rose.
Container ship charter rates peaked in 2005 and generally stayed strong until the middle of 2008, when the global financial crisis pushed rates to 10-year lows.
The estimated one-year time charter rate for a 3,500 TEU containership at the end of January 2010 was US$5,500 per day compared to an average of US$26,902 per day in the period 2000-2009. Time charter daily rates improved 99 per cent during the first nine months of 2010. By the end of September 2010 rates had recovered to US$19,000 per day.
Following an initial public offering on November 4, 2010, Costamare began trading on the New York Stock Exchange. Its shares last traded at US$12.10, which is near the offer price of $12 a share. The offer price was below from the US$15 to US$17 a share range in the prospectus, indicating poor demand for the shares.
Costamare purchased the 53 ship-owning companies held by the Konstantakopoulos family from Greece, comprising Captain Vasileios Konstantakopoulos and three sons Konstantinos Konstantakopoulos, Achillefs Konstantakopoulos and Christos Konstantakopoulos.
The sons owned 77.1 per cent of Costamare after its listing.
When it began the company owned and operated drybulk carrier vessels but since 1992 it has focused exclusively on container ships.
Since assuming management of the company in 1998, Konstantinos Konstantakopoulos has founded the management companies CIEL and Shanghai Costamare, and a manning agency C-Man Maritime. CIEL is the technical manager of Rena.
The vessel owners are wholly-owned subsidiaries incorporated in the Republic of Liberia and each vessel is managed by at least one of the three management companies. Rena is owned by Daina Shipping Co.
The company argues that by providing container ships to shipping lines under multi-year time charters it is not subject to seasonal variations in demand.
There are over 200 shipping liner companies, but the top 10 have 56 per cent of the market. AP Moller-Maersk's deployed fleet accounted for approximately 13 per cent of the global fleet liner capacity.
The Rena is a relatively small containership as Costamare has new vessels on order capable of carrying 9,000 containers.