The M/V Chenega up on blocks in drydock at the Ketchikan Shipyard for maintenance and repairs. The Chenega is one of two fast ferries in the Alaska Marine Highway System. The ship has a service speed of 32 knots.

The ferry Chenega undergoes repairs at the Ketchikan Shipyard in 2014. It’s back for an overhaul, which is taking longer than planned. (Photo by Heather Bryant/KTOO)

Sitka and Juneau will lose a week of fast ferry sailings this month.

The Chenega will return to Southeast service May 14, a week later than scheduled.

The vessel has been undergoing an overhaul, which includes replacing its engines.

Alaska Marine Highway spokesman Jeremy Woodrow says the Chenega turned out to have corrosion in its starboard hull. It’s being patched up for the season at the Ketchikan Shipyard, with permanent repairs planned for later this year.

“This temporary fix will be fine and it’ll be safe enough and it will be certified by the Coast Guard to run passenger service. And that way, we can get the vessel out sooner than if we had to do a major repair to this area where there is a little bit of corrosion found,” he says.

The ferry usually sails in Prince William Sound. But it’s scheduled to fill in this month for the Fairweather, its sister ship, which is having an engine replaced.

The Chenega will miss four Juneau-to-Sitka roundtrips May 7-10. Its first sailing on that route, May 14, includes a stop in Angoon. Its first Juneau-to-Petersburg roundtrip is scheduled for May 15.

Woodrow says reservations staffers are contacting affected passengers.