While the proven Zacks Rank places an emphasis on earnings estimates and estimate revisions to find strong stocks, we also know that investors tend to develop their own individual strategies. With this in mind, we are always looking at value, growth, and momentum trends to discover great companies.Looking at the history of these trends, perhaps none is more beloved than value investing. This strategy simply looks to identify companies that are being undervalued by the broader market. Value investors use tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.Zacks has developed the innovative Style Scores system to highlight stocks with specific traits. For example, value investors will be interested in stocks with great grades in the "Value" category. When paired with a high Zacks Rank, "A" grades in the Value category are among the strongest value stocks on the market today.One company to watch right now is Capital Product Partners (CPLP). CPLP is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock has a Forward P/E ratio of 3.36. This compares to its industry's average Forward P/E of 3.92. CPLP's Forward P/E has been as high as 7.55 and as low as 3.33, with a median of 5.40, all within the past year.Another notable valuation metric for CPLP is its P/B ratio of 0.59. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. This stock's P/B looks solid versus its industry's average P/B of 0.98. Over the past 12 months, CPLP's P/B has been as high as 0.65 and as low as 0.39, with a median of 0.53.Finally, we should also recognize that CPLP has a P/CF ratio of 2.33. This data point considers a firm's operating cash flow and is frequently used to find companies that are undervalued when considering their solid cash outlook. This company's current P/CF looks solid when compared to its industry's average P/CF of 5.87. Over the past 52 weeks, CPLP's P/CF has been as high as 2.71 and as low as 1.74, with a median of 2.18.Danaos (DAC) may be another strong Transportation - Shipping stock to add to your shortlist. DAC is a # 1 (Strong Buy) stock with a Value grade of A.Danaos also has a P/B ratio of 0.83 compared to its industry's price-to-book ratio of 0.98. Over the past year, its P/B ratio has been as high as 1.19, as low as 0.49, with a median of 0.81.These figures are just a handful of the metrics value investors tend to look at, but they help show that Capital Product Partners and Danaos are likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, CPLP and DAC feels like a great value stock at the moment. Zacks Names "Single Best Pick to Double" From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all. As one investor put it, “curing and preventing hundreds of diseases…what should that market be worth?” This company could rival or surpass other recent Zacks’ Stocks Set to Double like Boston Beer Company which shot up +143.0% in little more than 9 months and NVIDIA which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Capital Product Partners L.P. (CPLP): Free Stock Analysis Report Danaos Corporation (DAC): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research