BALTIMORE -- The Port of Baltimore's new deeper channels are ready to go, thanks to a four-year, $227 million dredging project.

The 57 miles of channels connecting Baltimore with the Atlantic Ocean at the mouth of the Chesapeake Bay have been deepened from 42 feet to 50 feet.

However ships won't make maximum use of the increased depth right away.

The Association of Maryland Pilots has decided to impose a 45-foot restriction for now.

Pilots, who guide big ships through the channels, need time to gain experience operating in the new channel system, said Michael R. Watson, president of the pilots association.

Before, ships were loaded to a depth of up to 41 feet. The new loading limit is 44 feet, which should still mean a substantial increase in the amount of cargo a ship can load or discharge in Baltimore.

The new depth should allow ships to carry an additional 8,000 tons to 13,000 tons of cargo. That's approximately a 10 percent to 15 percent increase, said C. Richard Foster, vice president of John S. Connor Inc., a steamship agent.

Jeffrey A. McKee, the Army Corps of Engineers official who managed the dredging project in Baltimore, said the new depth should help the port compete more effectively with Norfolk for coal shipments.

Norfolk has had a 50-foot channel for about two years.