Cardinal resident Leonard McLaren has come to see the CSL Assiniboine every day for the past three days. (Steve Fischer/CBC)

Hundreds of curious onlookers have been gathering on the shore of the St. Lawrence River in eastern Ontario to watch tugboats try to free a large ship that ran aground this week.

"This don't go all the time so everyone is wondering how they're going to get it out of here and I'm wondering the same thing," said Leonard McLaren, who has come every day for the past three days to see the Canada Steamship Lines vessel Assiniboine.

The ship, which is built to carry 30,000 tonnes, became stuck near Cardinal, Ont., about 50 kilometres west of Cornwall, while heading toward Quebec with a load of soya Monday morning. There were no spills or injuries.

According to Richard Corfe, president of the St. Lawrence Seaway Management Corp., the ship had lost both its engines and strayed into an area of water just seven metres deep. The 225-metre-long, self-unloading bulk carrier has a draft of about eight metres, which why it is wedged into the mud bottom.

Tugboats have been working to free the ship since Monday. (Steve Fischer/CBC)

"It's pretty stuck at the moment," Corfe said.

McLaren estimated Thursday that about 300 or 400 people came down to the shore to watch the tugboats at work the day before.

"It might be here for another week so there'll be lots of excitement going on here for a while yet."

Corfe believes the ship will be gone within a couple of days, although he admitted that freeing it won't be easy.

The ship will likely have to be unloaded.

"It's something that obviously will take some time to sort out," he said. "A vessel like this is carrying 30,000 tonnes. It's equivalent to a thousand trucks or three trains — imagine having 1,000 or even 10 trucks turned over on the highway or a train derailed."

In the meantime, while the incident is costing Canada Steamship Lines money, it isn't affecting other traffic on the St. Lawrence as it is outside the shipping channel, Corfe said.

About 3,000 ships pass through that section of the seaway each year. Corfe estimated there are 10 to 12 incidents involving those vessels each year, but few are serious.

The last time the seaway management corporation had to unload a vessel to get it off a shoal was in 2006.