Air-cushioned hovercraft vessels, long popular in Europe but little used in the United States, could be the answer for a trio of East Bay cities that long have sought ferry service to San Francisco.
Although a number of bureaucratic, political and physical hurdles remain, the Bay Area's water transit agency is exploring whether hovercraft are a viable option for ferrying passengers from Hercules, Martinez and Antioch, among other cities.
The vessels are appealing for several reasons: They are touted as more fuel-efficient than traditional catamaran ferries and as fast as the most advanced catamarans. Hovercraft also can navigate in shallow waters, even onto beaches and landing platforms, allowing them to reach areas that catamarans can't and respond to emergencies and provide service to cities saddled with shallow shorelines. Hovercraft travel on a cushion of air created by downward-thrusting air jets, while propellers mounted above deck provide forward propulsion.
Technological advances also have reduced concerns about noise and comfort that plagued hovercraft when they were introduced in Europe decades ago.
But to establish themselves in the Bay Area, hovercraft need to overcome a fundamental presumption shared by mariners and watercraft builders alike -- including a leading hovercraft manufacturer.
"As a general rule, if you can make all the connections you need using a (conventional) boat, without going around extended areas
Hercules sees hovercraft as the panacea for a shoreline of mud flats -- extending more than a half-mile into San Pablo Bay -- that would require costly dredging for traditional ferry service. Martinez also could require dredging, and Antioch looks to the speed of hovercraft to get passengers quickly to San Francisco, although experts, including some hovercraft specialists, say newer models of ferry catamarans match hovercraft's speed.
Antioch's and Martinez's interest in an idea fueled primarily by Hercules' lack of docking facilities addresses one crucial concern of the San Francisco Bay Area Water Emergency Transportation Authority -- that a "radical change" to hovercraft be justified over multiple routes.
It would require incorporating San Francisco into a baywide hovercraft system -- a daunting prospect at an Embarcadero terminal already busy with surrounding heavy marine traffic, and where space would need to be set aside for a hovercraft landing ramp.
Michael Bernick, a lawyer who has worked on the idea as a consultant for the East Bay cities, says a recent feasibility study completed by the water transportation authority shows the potential of hovercraft in the Bay Area.
"My own view is that it's doable," said Bernick, a former BART board member. "There are legitimate questions, but I think they can be addressed."
Questions include creating a separate or hybrid maintenance facility for hovercraft and conventional ferries and a docking facility in San Francisco. A memo written earlier this year by transportation authority officials acknowledged that hovercraft "would require wholly different operations practices and materials, as well as different docking facilities and maintenance berths."
But state Sen. Mark DeSaulnier, D-Concord, agrees that those challenges could be overcome.
"After seeing the study, hovercraft seems like a very feasible option," said DeSaulnier, who heads the Senate's transportation committee.
Bernick says the cost of operating hovercraft would be similar to traditional ferry vessels, and he noted that they would offer advantages in responding to emergency situations, an integral part of the transportation authority's mandate.
"The (transportation authority) board has been very open to the idea of a system with both (types of) vehicles," Bernick said.
The hovercraft's emergency capabilities, along with ecological advantages, make it an attractive prospect for the Bay Area, agreed Keith Whittemore, president of Seattle-based Kvichak Marine Industries, which built a hovercraft used in Alaska and the newest catamaran ferries in the Bay Area.
"From an emergency standpoint, you can pick people up from a downed bridge or a downed airplane and drive them onto a beach," he said.
Whittemore also noted that hovercraft are more fuel-efficient than catamarans at high speed but generally come with higher maintenance costs.
Unlike other existing or planned Bay Area ferry stops under the jurisdiction of the transportation authority, Hercules has no deep-water dock, nor any deep water where it could build one, that could accommodate conventional, deeper-draft boats -- a predicament apparently largely overlooked when the agency's predecessor, the Water Transit Authority, put together its expansion list starting in the early 2000s.
Dredging a deep-water harbor in Hercules for conventional ferries would cost "upwards of $17 million" initially and about $3 million in maintenance dredging every two to three years thereafter, according to the June 2 transportation authority memo.
"For Hercules, that makes a hovercraft financially more viable," Whittemore said.
Nevertheless, he says landing hovercraft at the San Francisco Embarcadero is fraught with challenges.
"You've got winds, tides, traffic -- that would not be a simple thing. That needs to be very carefully studied."
Hovercraft also could save Martinez dredging costs, Mayor Rob Schroder said.
The city's shoreline requires dredging on a regular basis, he said. Consultants from the transportation authority are studying the depth of the waters along the Martinez shoreline to locate a possible ferry terminal site. One of the potential locations is an old fishing pier, which likely would not require dredging.
The April feasibility study commissioned by the transportation authority estimated that travel time between Antioch and San Francisco could be cut to a little more an hour -- or about 30 minutes faster than traditional ferries used in the bay.
"That time reduction makes (the hovercraft) pretty competitive and a lot more appealing," Antioch Councilman Gary Agopian said.
But experts say technological advances in conventional watercraft have largely nullified hovercraft's erstwhile speed advantage.
The newest high-speed ferry from Vallejo to San Francisco, put in service in 2004, has a service speed of 34 knots fully loaded and a maximum speed of 38 knots, according to the website of Baylink, the route operator. By comparison, hovercraft envisioned for that crossing would travel at 40 to 45 knots, according to the feasibility study.
Hovercraft's greater susceptibility to headwinds could reduce any speed advantage, said John Sindzinski, the transportation authority's planning and development manager.
One possible obstacle to popular acceptance of hovercraft in the Bay Area, Sindzinski said, is the notion that they are noisy.
Paul Edwards, Griffon's director of business development, traces that perception to a previous generation of hovercraft that used noisy turbines for propulsion. Those craft have been largely phased out, he said.
Advancements have also allowed for a smoother ride. A Kvichak-built hovercraft ferry based on a Griffon design connects King Cove on the Alaska Peninsula to an airport eight miles across a bay, weather permitting.
"I was on it when the wind was 35 knots, and I stood the whole time," King Cove Mayor Henry Mack said. "You can walk around."
For local leaders, the choice is simple. They want whatever vessel will at last make ferry service a reality for their cities.
"We're going to favor which ever option gets service to Martinez faster," Schroder said. "At the same time, Martinez will work together with Hercules and Antioch to find the best option for the region."
Hovercraft are being considered for ferry service in San Francisco Bay. Here's how the hovercraft compares with traditional ferry service now offered.
Feature Hovercraft Catamaran ferry
(BHT150) (M/V Solano)
Cost per vessel $12 to $14 million $11.8 million
Passenger capacity 150 300
Speed (knots) 40 to 45 34 to 38
Fuel per hour (gallons) 92-172 300
Crew members 2 (min.) 4
Sources: Griffon Hoverwork Ltd., Kvichak Marine Industries, Vallejo Baylink Ferry