Divers continued to comb through the waters off Cape Breton Tuesday after a car plunged off a ferry and into the bay Monday night, quickly drifting away in the strong current.

RCMP Sgt. Alain LeBlanc says the car drove from a dock at St. Ann’s Bay onto the ferry and picked up speed before plunging off the end of an upright ramp at around 8:45 p.m.

The make of the car or the number of occupants inside remain unknown.

“There’s very little information,” LeBlanc told CTVNews.ca on Tuesday. “It happened very fast and the ferry crew didn’t have a lot of time to look at (the) car.”

Staff Sgt. Craig Yorke of the Baddock RCMP detachment told reporters that a crew member on deck tried to get the driver’s attention, “but the person continued on up through the gates and over the side.”

The search for the vehicle began Monday night with divers from the local fire department and continued into the early evening on Tuesday.

LeBlanc said the RCMP Underwater Recovery Team arrived at the scene around 9:30 a.m. local time, but by Tuesday evening had yet to locate the vehicle.

Rescue crews spotted what looked like an oil slick in the water at approximately 10 a.m., which indicated the vehicle may have been submerged underneath. However, three dive teams inspected the site and came up empty.

LeBlanc added that the current in St. Ann’s Bay is quite strong.

"If it was a lake and there was no current, it would obviously be a totally different environment," LeBlanc told The Canadian Press.

"The last thing we want to do is put our officers at risk. They're looking for the vehicle, but at the same time we have to make sure it's safe for them to do so."

Firefighters also searched for the car along the shoreline.

The car went into the water about 20 metres from shore and was last seen about 200 metres from where it entered the bay.

Nova Scotia’s Transportation and Infrastructure Renewal Department said in a statement it is fully co-operating with the RCMP, and will also conduct its own internal investigation.

The Englishtown ferry, which the department described as “one of the province’s newest and busiest,” has been taken out of service until further notice. The ferry connects Englishtown and Jersey Cove, and has been in service since 2008.

Pam Menchenton, a spokesperson for the department, said the ferry does not have a surveillance camera, nor does the crew have a master list of passengers.

Police said no one has filed a missing person report, and the reason for the incident remains a mystery.

“Anything could happen,” Yorke said. “We don’t know what was going on in the mind of that individual at the time, or if it was a medical problem, or what.”

With a report from CTV Atlantic and files from The Canadian Press