Update: 8:05 a.m. EST: Cruise Critic has learned that much of the repairs and enhancements to Carnival Triumph will be done while the ship is in wet dock in Mobile. In late April or early May, the ship will sail, under its own power, to Freeport in the Bahamas, to complete the remaining repairs that need to be done while the ship is out of water in a dry dock facility.

(March 19, 2:45 p.m. EST) -- Carnival Triumph will remain out of service through early June, while Carnival Sunshine will debut later than scheduled, Carnival Cruise Lines announced. Both ships will undergo "significant" mechanical investments to improve operating redundancies. The enhancements also will increase the scope of hotel services that can run on emergency power. The system improvements are part of the fleetwide operational review Carnival Cruise Lines CEO Gerry Cahill announced during last week's Cruise Shipping Miami tradeshow.

Though both ships are out of service -- Carnival Triumph because of the fire last month and Carnival Sunshine for an extensive shipwide refurbishment -- a Carnival spokesman said the line needs more time to complete the additional enhancements to source materials and install the new systems.

An additional 10 sailings of Carnival Triumph have been canceled; the ship will return to service June 3, rather than April 18. Passengers on the affected voyages will receive full refunds, reimbursement of nonrefundable transportations costs and 25 percent discounts on future four- to five-day cruises. Customers who had been booked on a Carnival Triumph sailing scheduled between February 11 and April 13, and had rebooked on a now canceled sailings, also will receive an onboard credit of $200 per cabin.

The two initial sailings of Carnival Sunshine also have been canceled; the ship will debut May 5 instead of April 12. Passengers scheduled on the canceled cruises will receive full refunds, reimbursement of all nonrefundable travel costs and 25 percent discounts on a future cruises.

In a news release, Cahill apologized for the additional cancellations but said the line is "fully committed to applying the recommendations stemming from our fleetwide review and to make whatever investments are needed despite the difficult position to impact people's vacations."

Cahill added future scheduling changes will be minimal as the line is able to source materials and schedule installations more quickly moving forward.

Among the enhancements being added to the ships are systems that will better support continued power and hotel services, such as vacuum toilets, should "unexpected" issues arise; tweaks to the fire suppression and extinguishing systems also will be made.

According to Carnival spokesman Vance Gulliksen, these enhancements include a "variety of measures that involve, among other things, bolstering these ships' emergency generator power capabilities, strengthening protections surrounding key electrical systems and rerouting high voltage cabling to provide greater protection and help ensure power redundancy."

--by Dori Saltzman, News Editor