The U.S. Coast Guard took the unusual step this week of warning Washington State Ferries along with other commercial vessel operators about the dangers of counterfeit parts.

The warning comes after a ferry in North Carolina took on water after counterfeit bolts in the engine room failed, causing machinery connected to the propeller to shift and allow water to pour into the engine room.

The Coast Guard is aware of all sorts of counterfeit equipment, including bolts, fasteners, firefighting gear, and life-saving products, according to Lt. Sarah Rodino, an inspector with the Coast Guard.

"I think it has to be somebody trying to save a dollar," said Rodino. "A lot of times the vessel operator has no idea they've been sold a counterfeit part."

Counterfeit parts are generally less stable and constructed with poor quality materials compared to original, genuine parts.

Washington State Ferries only buys equipment and parts from the original manufacturer or other major suppliers, according to a spokesman.

The Coast Guard is urging vessel operators to be extra cautious.

"Counterfeits sometimes get into the mix," said Rodino. "People forge documentation. It's important to be on the lookout for that."