Hawai‘i Boater’s Hurricane and Tsunami Safety Manual
Hawai‘i Sea Grant
Hurricanes are the most severe of all tropical cyclones and have great potential for widespread destruction in Hawai‘i. This was demonstrated in 1982 by Hurricane Iwa and in 1992 by Hurricane Iniki. Total damages in Hawai‘i from Iwa were estimated at $250 million and from Iniki at $2.4 billion. Hurricanes impact coastal areas in particular, especially harbors and marinas, where they cause widespread damage to boats and marine facilities. The Hawai‘i State Civil Defense and the University of Hawai‘i Sea Grant College Program in cooperation with the Hawai‘i Department of Land and Natural Resources (DLNR), Division of Boating and Ocean Recreation have developed this manual to give Hawai‘i’s boaters the information they need to protect their lives and property when a hurricane or other severe storm threatens. The manual also includes a section on tsunamis, another serious threat to boaters and the marine community in Hawai‘i.
Most hurricanes that impact Hawai‘i originate off the coasts of Central America or southern Mexico and then move in a west-northwest direction toward the Hawaiian Islands. Some hurricanes have formed to the south and southwest of Hawai‘i and have threatened the islands. Whatever their source, hurricanes often dissipate before they reach the islands or pass to the south, east, or west. Storms that do not strike the islands can still cause significant damage through high surf and heavy rain, which can cause flooding and landslides. On occasion, hurricanes strike Hawai‘i, causing considerable damage. Hurricane Iwa in 1982 and Hurricane Iniki in 1992 were especially destructive, causing billions of dollars in damage, especially on Kaua‘i. In addition to the considerable damage on land, boats in the harbors were hit hard, with many of them tossed onshore like toys and completely destroyed. In the aftermath of these great storms, many members of the boating community felt that they needed specific guidelines for action – especially since, with Hawai‘i sitting in the Central Pacific hurricane corridor, the probability of another hurricane striking the islands is great. Thus, the original version of this manual was published in 1998.
For boaters, tsunamis pose a similar threat as hurricanes, so it is appropriate to address the tsunami threat in this manual as well. The tsunamis of 1946 and 1960, from the Aleutian Islands and Chile respectively, were the most damaging of recent history. The 1946 tsunami delivered damaging waves to all the Hawaiian Islands, while the 1960 tsunami’s damage was concentrated along the shorefronts of Hilo and Kahului. 2 Somewhat smaller was the tsunami from Japan in 2011, but even this was adequate to produce damage in all small boat harbors in the state. Currents produced by the 2011 tsunami were especially severe at Ke‘ehi Lagoon, where floating docks broke free and more than a hundred vessels were severely damaged or sunk.
This updated manual provides a summary of the actions boaters and other members of Hawai‘i’s marine community can take before, during, and after a hurricane or tsunami. It is intended to assist in preparing for and mitigating the effects of these hazards. It includes information on these events and their dangers, provides guidelines to develop a personal preparedness plan, and lists emergency assistance information (that is, phone numbers, radio frequencies, and hurricane evacuation shelter locations). The statements and procedures contained in this manual may be modified or supplemented to meet the specific needs of individual boat owners. It is intended that this manual complement state statutes, Hawai‘i administrative rules, county codes and ordinances, whose provisions shall prevail in the event of a conflict.