Hawaii Superferry announced its 350-foot catamaran will be in drydock an extra three weeks because of damage to the vessel's aluminum hull that occurred during the drydocking process.

The time also will be used to conduct additional maintenance identified during drydock, the company said.

The high-speed Alakai went in for repairs Feb. 13 and originally was scheduled to resume service on March 3. However, Hawaii Superferry yesterday canceled sailings through March 24 to complete the repairs and maintenance.

The company is accepting reservations for sailings on March 25 and later. Passengers holding reservations for the canceled voyages are being notified and offered rebookings or refunds.

Cracks in the auxiliary rudder housing were discovered during routine maintenance in late January and early February while the Alakai was idled by bad weather.

The rudder system helps the vessel make minor course adjustments at high speeds, providing a smoother ride for passengers.

Hawaii Superferry president and CEO John Garibaldi said the rudder problem is the result of a design flaw, and that staff from shipbuilder Austal USA came to Honolulu to assist with repairs, which involve strengthening the metal around the housing.

He said a similar vessel built by Austal recently experienced the same rudder trouble.

Terry O'Halloran, Hawaii Superferry director of business development, said the rudder repairs are expected to be completed in the next few days, but that work will continue on fixing the Alakai's hull, which suffered dents while it was being maneuvered into drydock by a tugboat and during the drydock operation.

He said the rudder and hull repairs are covered by warranty.

The repairs are being conducted under Coast Guard supervision and the vessel will undergo required inspections before resuming service.

The extended drydock period is the latest in a series of setbacks the ferry has experienced since relaunching Dec. 13, most related to rough winter weather.

Hawaii Superferry customers can check for travel updates at www.HawaiiSuperferry.com or by calling the reservations line at 1-877-HI-FERRY (1-877-443-3779) between 6 a.m. and 7 p.m. daily.