Former Miami Dolphins quarterback Dan Marino has been soaked as an investor in a digital media company founded by "Titanic" director James Cameron. The company is best known for creating a 3-D holographic image of the late East Coast rapper Tupac Shakur performing at the Coachella festival in Indio, Calif., in April.

But now Port St. Luice, Fla.-based Digital Domain Media Group, Inc. is a shadow of its former self, and Marino's 1.6 million shares in the company are worth bupkis. The company had been involved in special effects for films such as "Transformers" and the "Pirates of the Caribbean" franchise, but not even Cameron's clout and his $700 million net worth could rescue the company from insolvency.

Digital Domain went public 10 months ago, floating 5 million shares that were snatched up for $8.50. The price surged to $9.20 after Tupac's holographic "appearance" and ensuing deals to create a holographic Elvis for public performances and media projects, according to the West Palm Beach, Fla., ABC affiliate.

But the company violated lenders' terms and failed to convince even near-billionaire Cameron to provide enough capital to meet operating requirements.  

By the time Digital Domain went into Chapter 11 bankruptcy court on Tuesday, shares were worth 55 cents. By Thursday afternoon they were trading on the PINK sheets for 10 cents. Marino is estimated to have lost $13.6 million -- a considerable amount even for a retired football superstar who still holds 16 NFL records. Celebrity Net Worth says Marino's net worth is about $35 million.  

Marino is not alone in the world of failed NFL quarterback entrepreneurs. Here are five others that fumbled the investment ball.