OLYMPIA — State legislators said Tuesday they won’t commit to building three new 54-car ferries for the Keystone-to-Port Townsend run until they are convinced the design is up to the challenge of navigating the route’s rough waters.

Lawmakers said they’ve heard concerns from ferry operators, crew members and passengers about the maneuverability and handling of the Steilacoom II class vessels. The ferries are smaller and less powerful than the 80-year-old Steel Electric-class boats that until recently operated on the route.

The state last week began leasing one of the Steilacoom-class vessels from Pierce County in hopes of restarting car ferry service on the run, which stopped when the Steel Electrics were pulled from service on the eve of the Thanksgiving holiday travel rush.

“I hear people say it’s not safe. I hear people say it is safe,” said Sen. Mary Margaret Haugen, D-Camano Island, who is chairwoman of the Senate Transportation Committee.

“The issue is how it handles in really rough waters. We won’t know until we get it out and do the sea trial,” she said.

Rep. Larry Seaquist, D-Gig Harbor, who is a former U.S. Navy captain, said the waters on the route across Admiralty Inlet “can be pretty sporty,” but that doesn’t rule out use of a smaller car ferry.

“It just might not sail as often as the Steel Electrics,” he said. “If it is not safe for that particular vessel of that design and shape than we’re not going to buy it.”

State Transportation Secretary Paula Hammond said there is no question the boats can make the run safely, and she intends to be aboard during sea trials.

“We know the boat is safe and seaworthy and is of a standard acceptable on that kind of run,” she said. “The Coast Guard wouldn’t authorize that boat for that run if it was not safe.”

Sea trials are expected to begin the first week of February with service possibly resuming Feb. 8, said Steve Reinmuth, chief of staff at the state transportation department and acting director of Washington State Ferries.

Reinmuth spent part of Tuesday touring the Steilacoom II and talking with state ferry crews familiar with the waters it will be asked to transit.

“We are scouting it from top to bottom for ways we can build it smarter,” Reinmuth said. Among other things, the ferry system is exploring the possibility of extending the car deck enclosure on any Steilacoom-class boats it builds, to add protection against rough crossings.

But changes won’t be allowed to get in the way of building ferries quickly, he said.

“We just don’t have the luxury of time,” he said.

Gov. Chris Gregoire has proposed spending $100 million to build three of the ferries using a modified design of the Steilacoom II. The first new boat could be on the water in 2009, Hammond said.

Legislation was expected to be introduced today to enable the Department of Transportation to proceed in building one or more ferries for the route. The legislation requires the vessels to carry no more than 100 vehicles and all must be built in Washington.

Some longtime ferry users in Port Townsend say they’d be more comfortable riding Steel Electrics, despite the state’s decision to tie them up because of safety questions.

The new ferries seem too small, too underpowered and too low in the water, said Barbara Blowers, 62, a Port Townsend real estate agent.

“The Steel Electrics struggled to get across in the currents. That little ferry can’t do it,” she said.

Ferry crews have been raising questions and so far state officials seem to be listening, said Gordon Baxter, a maritime labor lobbyist who represents all but a few dozen of the state’s 1,600 union ferry workers.

“We are doing what we can to work with the state to make sure that the vessels are going to work,” Baxter said. “We want them to work. We want to get that route served.”

How many of the Steilacoom-class ferries are built, or if the money is poured into another model, depends on the trials.

“We will proceed with this boat. Whether we build more than one is to be decided,” Haugen said.

Rep. Barbara Bailey, R-Oak Harbor and Norma Smith, R-Clinton, who met jointly with Hammond last week, said their communities need a boat in the water as soon as possible.

Even if the 54-car boat isn’t perfect for the long term, “if it can be modified to safely and efficiently do the job in the short haul then it should be done,” Smith said.

“While we exercise concern, that is no excuse to bring this to a grinding halt,” Bailey added. “We have to go forward. We have to get a boat in the water.”