To truely diversify you should be looking into more than just equities in the stock market. To answer your question though, I think that water transportation (TBSI for example) are going to be REAL hot over the next 1-2 years. Water transportation companies have really been beaten up over the past year. A lot of them have P/E ratios of just 4.0. TBSI in particular is in more niche markets than the rest of its competitors making it attractive.
To truly diversify though you should look to invest in more than stocks. Having at least 10%-20% in managed futures is recommended by many professional investors. Real estate is also an obvious investment asset class. To learn more about managed futures visit
www.managedfuturesdepot.com.