Wednesday, September 16, 2009

Blog 20 -- Hilo Harbor Breakwater

In 1946, Hilo, Hawaii, was struck by a tsunami generated by an earthquake in the Aleutian Islands; it was struck again in 1960 by a tsunami generated by the great Chilean earthquake. That is why I assumed that the Hilo breakwater was built…..but no, it is much, much older than that.

The Hilo breakwater was actually constructed between 1908 and 1929 upon a submerged reef in Hilo Bay to protect against winter storms. In fact both tsunamis overtopped the breakwater. (A plan to increase its height was rejected partially because no one could assure the public that such a project would indeed protect them from another seismic wave; not to mention questions of aesthetics about a towering wall that would block views to sea.)


Ok, so what are breakwaters? According the US Army Corps of Engineers they are structures employed to reflect and/or dissipate the energy of water waves, thus preventing or reducing wave action in a protected area. They are used to create sufficiently calm waters in a harbor area, thereby providing protection for the safe mooring, operating, and handling of ships and protection of shipping facilities.

Why Hilo?

The growth of Hawaii during the establishment of sugar plantations and their use of immigrant labor and the up-and-coming visitor industry depended on the systematic development of secure harbor facilities. Hilo Harbor is one of two commercial harbors on the Big Island (the other is Kawaihae on the northwest side of the island). The first recorded improvement in Hilo was a stone pier constructed by an early entrepreneur, Thomas Spencer in 1861.

Hilo Harbor is located at Kuhio Bay, itself a small extension of the larger Hilo Bay. The harbor is two miles from the business district of Hilo and some 194 nautical miles southeast of Honolulu Harbor. Both overseas and inter-island ships and barges make regular calls at Hilo Harbor in addition to scheduled passenger cruise ships.

Blonde Reef

The submerged reef upon which the breakwater is built runs in the shape of a crescent, in a position reversed to the crescent of the bay. The average depth of water over this reef is about 23 feet, with occasional pockets of 40 or more feet depth.

It was named Blonde Reef in 1825 in commemoration of a visit by Lord George Byron, cousin of the poet. He arrived in Hawaii aboard the British frigate, H.M.S. Blonde which was carrying the bodies of Liholiho (King Kamehameha II) and his wife Kamamalu to Honolulu for burial there. The Hawaiian king and queen had died of measles within six days of each other while on a visit to London. Lord Byron proceeded to Maui and Oahu and returned to Hilo with Ka’ahumanu, regent of the kingdom. On their arrival Ka’ahumanu declared that Hilo Bay was henceforth to be known as Byron Bay, and from then on the reef that protects the bay has been known as Blonde Reef in honor of the ship that had returned the bodies of the royal couple to their homeland. (Beaches of the Big Island, John R. K. Clark, University of Hawaii Press, 1985).

Construction of Hilo Harbor Breakwater

The United States entered into a contract on June 12, 1908, for constructing the breakwater at Hilo Harbor. The specifications called for a jetty of the rubble mound type (rubble-mound breakwaters are the largest and most substantial of various breakwater types and are used almost exclusively in offshore and major coastal harbor protection schemes.)

Many stones in the slope walls were required to weigh more than two tons each. And across the top and down the sea side slope, to a point three feet under low water, the stones needed to weigh over eight tons each!

The required weight for the stones sent the contractor nearly thirty miles to Puna, on the east point of the island, to open a quarry. For while the whole island is virtually built of flows of lava rock, and the breakwater itself rests on a reef of it, there are comparatively few places on the slopes of Mauna Loa where rock of this weight could be found in large quantities. Nearly four miles of railroad had to be graded and built across lava flows in order to make connections with the tracks of the Hilo Railroad Company over which the stone was hauled.

The breakwater was completed in three sections respectively in 1910, 1911 and 1929. The third section extended the breakwater to its present length of about 2 miles. After dredging a deepwater channel in 1914 and from 1925-1930, the Hilo Harbor took roughly its present form.

In the 21 years of its construction the breakwater ended up using over 950,000 tons of rock -- truly a feat of engineering and worthy of our esteem for all involved. Mahalo !

Nā pana kēia o Keaukaha

Mai ka palekai a I Leleiwi

Pā mau I ka meheu a nā kūpuna.

Ha’alele aku ‘oe I ka palekai

Kahi māka ‘ika’I e nā selamoku

Lana mālie ke kai’ olu nā lawai’a.

These are the famous places of Keaukaha

From the breakwater all the way to Leleiwi

Resounding to the footsteps of our ancestors.

Your leave the breakwater,

The place visited by sailors.

Where the sea lies calm, the fishermen are pleased.

“Na Pana Kaulana o Keaukaha”

© by Edith Kanaka’ole, 1979


  1. Amazing information! Thanks for doing the digging!

  2. Nice blog! My family is mostly on the mainland now (we visit Hilo every now and then), but my tutu's grandpa engineered part of the Hilo breakwater. If you're interested, check out our website for more info


  3. Wes, this was nicely done - great blog!

    Carrie Rojo


Mahalo for leaving a comment!~WesIsland