NEW YORK (TheStreet) -- Shares of DryShips  (DRYS) are sinking by 43.22% to $1.34 on Tuesday afternoon, on concerns that the Greece-based global ship operator is going under.

DryShips said it had "substantial doubt about the company's ability to continue," according to a recent Securities and Exchange Commission filing.

DryShips defaulted on three loan payments, amounting to $213.667 million through March 2017. The payments due exceed the company's overall capital of $146,340 million, according to USA Today.

"Given the prolonged market downturn in the drybulk segment and the continued depressed outlook on freight rates and vessels' market values, cash expected to be generated from operations or proceeds from the sale of vessels, assuming that current market charter hire rates would prevail in the twelve-month period ending March 31, 2017, will not be sufficient to cover the company's working capital deficit," DryShips said in the securities filing.

The company had an amount of $280 million in total liabilities as of March 31, 2016.

DryShips owns a fleet of 23 drybulk carriers, comprised of three Capesize and twenty Panamax, and six offshore supply vessels.

Separately, TheStreet Ratings rated DryShips as a "sell" with a score of E+.

This is based on a variety of negative investment measures. The company's weaknesses can be seen in multiple areas, such as its generally high debt management risk, disappointing return on equity and generally disappointing historical performance in the stock itself.

You can view the full analysis from the report here: DRYS

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.