A barge loose in the harbor is a Coast Guard responsibility, said Lt. John Titchen of the Coast Guard in Honolulu. Since the barge at rest is considered a permanently moored vessel, the Coast Guard has no authority to inspect or approve its mooring arrangements.

However, the Coast Guard was consulted by the state Department of Transportation about the plan to install the barge as a docking device for the ferry, Titchen said. Coast Guard specialists commented that berth 2C – where the docking barge was moored – is "not the best."

With its entrance channel opening to the north, Kahului Harbor is one of the few harbors in which there is a regular surf break. Berth 2C at the tip of Pier 2 is the most exposed to swells coming through the entrance channel.

On Wednesday, the islands were swept with 4- to 6-foot northwest swells generated by a pair of storms moving across the north Pacific. They were enough to snap one of the chains or cables holding the barge to the pier.

The barge was corralled by two tugs after several hours, with minor damage to the barge and the pier. But the barge was moved to berth 2B, which is less exposed to swells.

Once the barge was loose, the Coast Guard was informed, said Titchen, and the duty officer was on hand. An incident report will be completed, as is done for any event that creates a potential hazard to navigation.

In recent years, there have been three incident reports at Kahului Harbor about barges that were involved in collisions or near misses. None resulted in serious damage, oil spills or interference with port operations.

Titchen said the Coast Guard did inspect and certify the Alakai, the Hawaii Superferry's first vessel, when it arrived in Hawaii, in a "new to zone" procedure, because it will be traveling waterways under Coast Guard jurisdiction.

The docking barge, which is owned by the state, is under state jurisdiction.

It is semipermanently moored to the end of Pier 2. The DOT and the Hawaii Superferry operating plan contemplated having to move the barge occasionally when swells and surge become a problem in the harbor.

That happens more often when winter storms sweeping across the north Pacific and Gulf of Alaska send swells down from the northwest and north.

When swells barrel down the entrance channel, the surge within the harbor can create problems. Last December, ships straining at their mooring lines plucked four huge bollards off two piers.

While the swells and surge were not as severe this week, state transportation spokesman Scott Ishikawa said Friday that the Harbors Division will be monitoring the effects of surge on the barge closely.

Dave Ward, president of the Hawaiian Canoe Club, said his club has taken a neutral stance about the Superferry, but "safety is a big concern" for recreational users of the harbor.

"I am sure the DOT will check out alternatives and have a strong safety policy," Ward said.

There were paddlers as well as surfers at play in the harbor when the chain or cable (it is not clear which) gave way with a report of an explosionlike sound about 4 p.m. Wednesday.

Ward says one of his members on the water was spooked by the impressive noise, but no one was in danger.

Ward said he noticed about a week and a half ago that harbors personnel appeared to replace rope mooring lines on the barge with chains.

Ishikawa said the barge uses three types of moorings – rope, chain and steel cable. The cable is installed to allow the mooring to be tightened when the docking barge is in use by the Superferry.

"The trouble with cable is that it has no slack, so when there is a lot of pressure, it can snap," he said.

The chains and rope allow more give in the moorings when the barge does not need to be held tightly to the pier. Ishikawa said harbors personnel could not say why the cable and chain snapped on Wednesday, but he said they will be monitoring the mooring system closely.

With the Harbors Division having to plan for increased traffic into Kahului, there have been a number of proposals for reducing surge as part of the development of a 2030 Kahului Harbor Master Plan.

Among the proposals under review are changes to allow use of the west breakwater – currently used only for a small-boat launching ramp. With a periodic surf break just inside the west breakwater, surge along the breakwater makes it unusable by ships and barges.

Proposals to reduce surge include cutting a notch or building a jetty to create a sheltered space along the west breakwater. There have been other studies of ways to prevent surge by building huge baffles outside the harbor, but all proposals are expensive and none has been adopted.

Harry Eagar can be reached at heagar@mauinews.com.