Hundreds of boats were left damaged, drifting or sunk and numerous vessels stuck offshore without a safe place to moor because some harbors remain closed due to debris in the water and damaged piers, according to a U.S. Coast Guard assessment of this morning’s destructive tsunami.

No one in Hawaii was killed or injured, but the tsunami’s many surges caused extensive damage  on three islands.

The Coast Guard said 200 boats  at Keehi Small Boat Harbor near Sand Island were affected after docks broke free from their moorings with the boats still attached. Many of the boats floated aimlessly in the lagoon, colliding with each other and in one instance, slamming into the Sand Island Bridge.

"Some are pushed up on other vessels," said Lt. Gene Maestas, a Coast Guard spokesman. "It’s a variety of damage."

At Maui’s Maalaea Harbor, two vessels sunk and a third overturned, Maestas said.

Tsunami waves from a massive Japanese earthquake began hitting Hawaii just after 3 a.m. today after an hours-long statewide coastal evacuation. 

The Coast Guard sent two HH65 helicopters aloft at first light and this afternoon planned to send a C-130 airplane to the Big Island. Small boat crews also inspected the harbors.

Although Oahu harbors are open, harbors on Maui and the Big Island remained closed, Maestas said.

"The vessels that went offshore last night to make sure they didn’t get caught in the surge are still out there," he said. "Right now we are looking for a safe location where they can moor. We have a lot of debris in those harbors. There are quite a lot of things that need to be done before we can open those harbors."

 Honolulu Mayor Peter Carlisle has issued an all clear for Oahu about 8 a.m. Carlisle said city officials waited until after daybreak to assess the situation before declaring it is safe to return to the coast.

At midday, however, Maui County remained under a tsunami advisory. 

On the Big Island, the King Kamehameha Kona Beach Hotel got a foot of water in the lobby and canoes in the harbor were destroyed. Flooding was also reported in Kahului.

The waters continued to surge in some harbors hours after the initial wave hit.

Indeed, one witness reported a surge at Keehi Lagoon about 5:40 a.m.

Kauai also issued an all clear.

Gerard Fryer, a scientist with the Tsunami Warning Center, said an initial 6-foot surge was detected in Kahului Harbor, and Fryer said a second surge was more than 7 feet at Kahului Harbor.

At Napoopoo at Kealakekua Bay on the Big Island, one wave reached at least 100 feet inland and an elevation of 11 or 12 feet, Fryer said.

"It could have been more than that," he said.

The gauge at Nawiliwili Harbor showed a 2.1 foot surge; Haleiwa recorded a 3.6 foot surge; and Hanalei recorded 2.8 feet. The weather service says a gauge at Hilo Harbor showed a 2-foot surge. Kawaihae saw a 2.8 foot increase.

Off Diamond Head lookout, the water receded twice — once about 3:43 a.m. and again at 3:55 a.m. — exposing reef, before waves rushed back to the high water line.

More than 100 spectators gathered at the lookout to see the waves come in, and many ‘oohed’ and ‘ahhed’ when the near-shore reef was fully exposed in seconds.

"It was creepy," said Mike Moylan, 42, who had to evacuate his home on Kuhio Avenue and so decided to watch the waves at Diamond Head. "Seeing the water recede that much, it’s scary."

Chana Dudoit, 28, of Kaimuki, saw the waves receding on TV and decided to rush out to see them in person. "I thought it was crazy," she said. "Where did all the fish go?"

A tweet from the Pacific Fleet said a surge of more than 1.5 feet was detected at Pearl Harbor. No damage was reported.

The tsunami was generated from an 8.9-magnitude quake in Japan.

The weather service reminded people that there will be a series of waves and the first wave may not be the biggest.

The Pacific Tsunami Warning Center issued a tsunami watch at 7:56 p.m. after the quake struck 231 miles northeast of Tokyo.

Chip McCreary, director of the warning center, said because of the long length of tsunami waves, "they wrap around our islands very efficiently" so there is no point of impact that may see higher waves than other areas.

"There are some places that will be affected more than other places," McCreary said. "From our history, we’ve had bigger impacts in Hilo, Kahului and Haleiwa and our models bear that out."

Even before civil defense sirens sounded just before 10 p.m., people were lining up to get gas around Oahu. Police dispatch reported arguing over gas in Ewa Beach and lines to get gas on Fort Weaver Road.

About an hour after the quake struck, Jake Chang, of Papakolea, was at the Aloha gas station on Vineyard Boulevard filling up his truck and a plastic gas container to power his generator.

"I was watching TV," he said. "I saw the footage of Japan. It was unreal."

Hawaiian Electric Co. opened its emergency command center and implemented its tsunami plans, according to Peter Rosegg, Hawaiian Electric spokesman.

Striking members of the International Brotherhood of Electrical Workers are still out, Rosegg said, adding that the electric company has an agreement with the union that workers will return to work in case of a "major emergency."

"We have an agreement, but until we know the extent of the emergency we will not know what we need," Rosegg said.

Meanwhile, HECO is moving its emergency vehicles to higher ground and Rosegg said it is shifting generation to facilities that are the least threatened by a tsunami.

"We are prepared with nonunion and management crews," Rosegg said.

About 1,300 IBEW members went on strike Friday.

In 1854, an earthquake measuring 8.4 on the Richter scale devastated the region from Tokai to Kyushu and killed an estimated 10,000 people. In 1896, an 8.5-magnitude earthquake hit the Sanriku coast; the earthquake and the resulting tsunami killed some 27,000 people.

Tsunami waves were reportedly observed in Hawaii and California, but no significant damage was reported. 

And in 1946, an 8.1-magnitude quake hit Nankaido, killing 1,362.

Over the last century, tsunami have killed hundreds of people and caused millions of dollars of damage in Hawaii. The worst took place in 1946 when a 7.1-magnitude earthquake in the Aleutian Islands resulted in a tsunami that flooded downtown Hilo, killing 159 people. Hilo was hit again in 1960 when an 8.3-magnitude quake in Chile generated waves of up to 35 feet that destroyed buildings and caused 61 deaths.

The last significant tsunami in Hawaii occurred in 1975 when an earthquake off the Big Island generated a 26-foot wave that killed two people and injured several others.