Half of the city's new commuter ferry fleet won't be quite ship-shape when service between Kalaeloa and Aloha Tower begins Monday.

One of the two leased vessels has not yet been cleared for operations in Hawaiian waters, and won't be ready for at least one more week, officials said.

The service, dubbed TheBoat, will offer two ferry trips a day in each direction, instead of the planned three, until the second vessel is ready.

An express bus will take the place of the missing 6 a.m. ferry in the meantime, and carry passengers from Kalaeloa Harbor to Aloha Tower.

Commuters who planned to take the 5:20 p.m. ferry from Aloha Tower back to Kalaeloa can catch special buses from the tower to their West O'ahu destinations.

The glitch was announced late yesterday, after months of planning the $6 million, one-year demonstration program.

"After extensive testing in Hawaiian waters, we are 100 percent confident with one vessel's performance and reliability," said city transportation director Melvin Kaku. "We want to make sure the second vessel that arrived in Honolulu a week later goes through the same rigorous testing, so we're taking this extra time instead of rushing it into service."

Passengers can view one of the boats at a dockside open house tomorrow, from 10 a.m. to 2:30 p.m. at Pier 9 by Aloha Tower. Officials will distribute information and answer questions.

No parking will be available at Kalaeloa Harbor as the service begins, but the city plans to soon provide 30 secure park-and-ride stalls in the Kapolei area, which will be linked to the Kalaeloa Harbor by feeder buses, Kaku said. Twenty additional stalls may soon be available at the harbor.

The main idea of the ferry program has been to build links to other public transportation services, however.

The ferries will be linked at Kalaeloa to new city bus routes serving Wai'anae, Kapolei and Makakilo.

From Aloha Tower, buses will go to the University of Hawai'i-Manoa and to Waikiki via Ala Moana.

A single fare will pay for the entire journey: the one-hour ferry ride and buses at each end. The one-way fare for adults is $2, and bus passes also will be honored.

A plan awaiting final City Council approval would offer free rides from Sept. 24 through Sept. 28 on the ferries and new bus lines.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.