While the interisland Hawaii Superferry remains anchored in controversy, a new commuter ferry service for O'ahu's South Shore is about to get under way.

The second 149-passenger vessel for the new program arrived in Honolulu Harbor this week, and Mayor Mufi Hannemann today will announce the date of their maiden voyages in Hawaiian waters.

The twin 72-foot aluminum catamarans, named the Melissa Ann and the Rachel Marie, will make a total of three daily trips in each direction from Barbers Point Harbor in Kalaeloa to Aloha Tower in Downtown Honolulu.

The Melissa Ann arrived earlier this month, and planners have been aiming to start the service by Sept. 17, after earlier launch dates were pushed back amid questions about the program's efficiency and a lack of parking at Barbers Point.

In a letter sent several months ago, the Federal Transit Administration worried that parking woes "will severely limit the ability of the ferry service to appeal to a broad segment of the commuting public."

But city officials say the main idea is to link the service to existing public transportation, as an alternative to driving. The service has been dubbed TheBoat, a nod to TheBus.

The FTA has released the first installment of a federal grant package expected to total $5 million.

The ferries will be linked at Barbers Point 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.

The ferries previously sailed in waters off Alaska and Washington state, and will be operated here by Hornblower Marine Services.

The ferries are expected to run for at least one year, and the service could be extended if it proves successful. The city is also studying whether a ferry stop can be added at Iroqouis Point.

At least three coastal ferries plied similar routes in recent memory but did not include direct bus links.

The state operated the WikiWiki Ferry from Kalaeloa to Aloha Tower for about a year, ending in 2000. A combined average of 100 passengers rode every day at the high point. But toward the end — when a $3 million federal grant was running out — some of the 136-passenger boats carried fewer than 20 people.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.