Tsunami evacuation for harbors, marinas, and boats¶

Tsunamis present a catastrophic hazard to mariners, harbor masters, and coastal vessel operators. When subduction zone earthquakes, submarine landslides, or caldera collapses displace billions of cubic meters of seawater, long-period gravity waves radiate across ocean basins at jetliner velocities exceeding 800 kilometers per hour (500 miles per hour). In the open ocean, these waves pass beneath vessels almost imperceptibly, measuring less than 1 meter (3 feet) in height across wavelengths spanning 100 to 200 kilometers (62 to 124 miles).

As a tsunami enters shallow coastal waters, continental shelf friction compresses the wavelength, dramatically slowing wave velocity while forcing wave height to skyrocket through shoaling. Within enclosed harbors, narrow shipping channels, and shallow marinas, tsunamis transform into violent surges, standing vortices, and catastrophic water drawdowns. Marinas become lethal hydraulic washing machines where docks rip from pilings, grounded vessels smash together, and currents exceeding 15 knots (28 kilometers per hour or 17 miles per hour) crush anyone caught on moorings or attempting last-minute vessel salvages.

Cakava oqo ena gauna oqo¶

1. Evacuate moored vessels to high ground on foot immediately upon a local warning:
   • Abandon boats tied to docks, slips, or moorings the moment strong ground shaking occurs or a tsunami warning sounds.
   • Run inland and uphill immediately, reaching elevations at least 30 meters (100 feet) above sea level or moving 3 kilometers (2 miles) inland.
   • Never waste time attempting to start engines, cast off mooring lines, or save personal maritime property when wave arrival is within two hours.
2. Sort vessel actions by water depth if already underway at sea:
   • If operating in deep water exceeding 183 meters (100 fathoms or 600 feet), remain offshore and steer directly into incoming long-period swells.
   • If operating in shallow coastal waters between 20 meters and 100 meters (66 feet and 328 feet), motor immediately toward deep water if at least two hours remain before wave impact.
   • If operating within a narrow bay, harbor approach, or shallow inlet with less than one hour of warning, beach the boat in a safe cove and run uphill on foot.
3. Never attempt to pilot through narrow harbor entrances during a warning:
   • Refrain from entering or exiting confined jetties, harbor mouths, or breakwaters once a tsunami alert is issued.
   • Avoid narrow harbor bottlenecks where hydraulic suction and compressed incoming surges create lethal standing bores and breaking waves.
   • Stand off in open, deep water beyond the continental shelf break until port authorities issue an official all-clear directive.
4. Monitor emergency marine telecommunications continuously:
   • Tune your marine VHF transceiver to Channel 16 (156.800 megahertz) and monitor National Oceanic and Atmospheric Administration weather radio broadcasts.
   • Coordinate offshore staging positions with the United States Coast Guard, port authorities, and regional rescue coordination centers.
   • Transmit your position, crew count, and vessel status to maritime safety networks before offshore cellular coverage drops.
5. Prepare for multi-day offshore isolation if remaining at sea:
   • Throttle back engines to minimum steerageway once in deep water to conserve diesel and gasoline supplies.
   • Ration drinking water and food provisions, anticipating that shore infrastructure, fuel docks, and harbor piers will be destroyed upon return.
   • Establish an anchor watch and maintain active radar sweeps to avoid floating shipping containers, detached marina docks, and drifting derelict hulls.

flowchart TD
    A["Tsunami Warning Issued: Earthquake Felt or Siren Sounds"] --> B{"Where Is Your Vessel Currently Located?"}
    B -- "Moored at Dock or Slip" --> C{"Time to First Wave Impact"}
    C -- "Less Than 2 Hours" --> D["Abandon Boat Immediately: Run Inland to 30m / 100ft Elevation"]
    C -- "More Than 2 Hours & Open Harbor" --> E["Evaluate Port Authority Directives & Evacuate if Mandated"]
    B -- "Underway Inside Harbor or Shallow Bay" --> F{"Can You Reach 183m / 100 Fathoms in Time?"}
    F -- "No: Less Than 1 Hour" --> G["Beach Vessel in Safe Cove, Evacuate to High Ground on Foot"]
    F -- "Yes: Open Deep Water Ahead" --> H["Motor Full Speed to Deep Water Beyond 183m / 600ft Depth"]
    B -- "Sa lako tiko ena wasawasa e sivia na 183m / 100 na vatu" --> I["Tiko ga e baravi ena wai titobu: Toso ki na Swells balavu"]

Fisika ni Sunami ni Wasawasa: Wasawasa Titobu kei na Shelf Titobu¶

Na kena qaravi vinaka e dua na waqa ena gauna ni sunami e gadrevi kina na kena kilai na mekaniki ni wai e lewa na ua balavu ni wai titobu. Dina ga ni dau lakova na sunami na veiwasawasa e udolu vakaudolu na mita na kena titobu, ia na vakadidike vakayago ni wasawasa e vakatokai me ua titobu baleta ni sivia sara na titobu ni wasawasa na kena balavu.

In deep ocean water, wave velocity depends directly on water depth, governed by gravitational acceleration. Over abyssal plains with depths around 4,000 meters (13,120 feet), a tsunami travels at approximately 200 meters per second (720 kilometers per hour or 447 miles per hour). Despite this speed, the wave steepness is tiny. A wave measuring 0.5 meters to 1 meter (1.6 feet to 3.3 feet) in height distributed over a wavelength of 150 kilometers (93 miles) produces a slope so gradual that ships at sea do not perceive the wave passing beneath their hulls.

Na veisau mai na ua lelevu ni wasawasa ki na ua ni baravi veivakarusai e yaco ena kena lutu na ua ena gauna e sotava kina na wasawasa na konitineni:

• Na lawa ni Green kei na kena vakalevutaki na ua: Ni sa lailai sobu na titobu ni wai, na totolo ni ua e vakalailaitaka ena kena veiganiti vakadodonu kei na yavu ni sikuea ni titobu ni wai. Me vaka ni dau tudei tikoga na gauna ni ua, e totolo cake na kena lako na daku ni ua mai na mua, ka vakamalumalumutaka na balavu ni ua. Me maroroi na kinetic kei na rawa ni kaukauwa flux, na cecere ni ua e tubu vakatautauvata ki na titobu ni wai e laveti cake ki na kaukauwa ca e dua na ikava, e dua na veiwekani vakafika kilai me lawa ni Green.
• Na Veivakamavoataki ni Balavu ni Wasawasa: Ena wai titobu, e dua na ulunivanua ni sunami e rawa ni 100 ki na 200 na kilomita (62 ki na 124 na maile). Ni sa vakalailaitaka na ua mai na 720 na kilomita ena dua na auwa (447 na maile ena dua na auwa) ena wai titobu ki na 36 na kilomita ena dua na auwa (22 na maile ena dua na auwa) ena baravi titobu, na balavu ni ua e vakamalumalumutaki ki na lailai mai na 5 na kilomita (3 na maile), ka vakasoqona na wai ki na veiulunivanua lelevu vakadodonu.
• Kinetic to Potential Energy Conversion: As the bottom of the water column drags against the shallow sea floor, horizontal particle velocity transfers upward, transforming immense kinetic momentum into hydrostatic head pressure. This process converts a smooth, rolling deep-ocean displacement into an onshore surge.

Within semi-enclosed water bodies, harbors, and bays, secondary hydrodynamics amplify destruction:

• Harbor Resonance (Seiche Dynamics): Every enclosed harbor possesses a natural oscillation frequency based on its geometry, depth, and entrance width. When the period of incoming tsunami wave trains matches the natural resonant frequency of the harbor basin, constructive wave interference occurs. Resonance drives water levels to oscillate violently for 24 to 48 hours, generating internal surge heights twice as high as the open coast.
• Bore Formation in Shallow Estuaries: When a tsunami enters a shallow river estuary or narrow bay, the front of the incoming wave steepens rapidly, forming a turbulent, foaming vertical wall of water known as a tidal bore or tsunami bore. Bores advance at 15 to 30 knots (28 to 56 kilometers per hour or 17 to 35 miles per hour), exerting immense destructive ram pressure against marine pilings and moored vessels.

The 100-Fathom Rule and Deep-Water Vessel Operations¶

Maritime safety agencies worldwide, including the National Oceanic and Atmospheric Administration, the United States Coast Guard, and the Japan Meteorological Agency, maintain a universal standard for offshore vessel survival: the 100-fathom (183-meter or 600-foot) depth contour rule.

Operating beyond the 100-fathom bathymetric contour line moves your vessel beyond the continental shelf break, where ocean floor depths transition rapidly toward abyssal plains. Beyond this depth threshold, tsunami wave transformation has not yet initiated:

When operating a vessel in deep water during an active tsunami alert:

• Steer Directly Into the Swell: Maintain your vessel's bow perpendicular to incoming waves. Even in deep water, the leading edge of a tsunami can produce steep swells as it traverses subsea ridges. Taking a steep swell on the beam introduces severe rolling and risks broaching or capsizing.
• Throttle Back to Conserve Fuel: Do not burn fuel unnecessarily by maintaining high cruising speeds once beyond the 100-fathom line. Throttle down to minimum steerageway, maintaining just enough forward momentum to preserve rudder authority and bow orientation into the prevailing sea.
• Disengage Autopilot Systems: Deactivate automated steering systems and maintain manual control of the helm. Tsunami wave trains produce long-period orbital water movements that can confuse fluxgate compasses and gyrocompass inputs, causing erratic steering maneuvers.
• Maintain Continuous Radar Watches: Tsunami backwash sweeps millions of metric tons of terrestrial debris into open coastal waters. Use marine radar tuned to short-pulse, high-resolution modes to track unlit hazards, including overturned hulls, broken pier sections, commercial shipping containers, and uprooted trees drifting offshore.

Marina and Harbor Dynamics: The Moored Vessel Crisis¶

Moored vessels face catastrophic destruction during a tsunami. Attempting to ride out a surge aboard a boat tied to a dock is one of the most common fatal errors made by mariners in coastal zones.

The destruction of marina infrastructure proceeds through rapid physical phases:

flowchart TD
    A["Tsunami Crest Arrives in Harbor"] --> B["Water Level Surges Upward at 1 to 3 Meters Per Minute"]
    B --> C["Floating Docks Float Above the Tops of Structural Pilings"]
    C --> D["Mooring Cleats Tear Out; Synthetic Lines Snap Under Shock Loads"]
    D --> E["Free-Floating Docks and Vessels Crash Inshore in Tangled Flotilla"]
    E --> F["Violent Drawdown Empties Basin: Vessels Ground and Roll on Bilges"]
    F --> G["Second Wave Hits Grounded Boats: Total Physical Hull Crushing"]

1. Piling Overtopping and Dock Failure¶

Modern marinas use floating pontoon docks held in lateral position by vertical steel, concrete, or wooden pilings. These pilings are engineered to accommodate historical astronomical high tides plus a standard storm surge safety margin, typically 2 to 3 meters (7 to 10 feet) above mean higher high water.

When a major tsunami surge enters a harbor, water levels rise at vertical rates exceeding 1 to 3 meters per minute (3 to 10 feet per minute). As the water level exceeds the height of the pilings, floating docks detach from their vertical guide sleeves. Once freed from their pilings, docks, gangways, utility lines, and hundreds of moored vessels become an unguided, multi-thousand-ton floating mass driven by high-velocity currents into shoreward breakwaters and bridges.

2. Mooring Line Snapping and Cleat Tear-Out¶

Even in harbors where pilings remain un-topped, the horizontal water velocity generated by tsunami surges exerts catastrophic drag forces on vessel hulls. Standard three-strand nylon or braided polyester dock lines are engineered to absorb gentle tidal surges and minor wind chop.

A 10-knot current rushing past a moored 12-meter (40-foot) displacement vessel generates thousands of kilograms of static lateral force. When turbulent surges alternate direction every 10 to 15 minutes, mooring lines experience violent cyclic shock loading. Synthetic lines stretch beyond their elastic limits, snapping with explosive force, while aluminum dock cleats tear out of fiberglass decks, launching metal projectiles across docks.

3. Rapid Water Drawdown and Keel Grounding¶

Tsunami wave physics dictates that if the leading wave of a tsunami train is a trough, the arrival of the wave is preceded by a dramatic, rapid withdrawal of water from coastal harbors. Water recedes at rates that can drain an entire harbor basin in less than 5 to 10 minutes, exposing the sea floor, anchor chains, and subsea pipelines.

Vessels moored in slips drop violently to the seabed, landing on their keels, rudders, and propellers. Deep-draft sailboats and twin-engine motor yachts heel over on their bilges, filling with mud and trapping crew members below decks. When the returning tsunami crest strikes the drained harbor basin minutes later, it acts as a breaking wall of water that slams into the rolled, grounded hulls before they can re-float, crushing cabins and drowning trapped occupants.

Real-World Case Studies and Nautical Lessons¶

Analyzing historical maritime tsunami disasters provides clear lessons regarding the lethal nature of harbor surges and the practical survival margins achieved by vessels that moved offshore.

The Great Alaska Earthquake on March 27, 1964, generated a trans-oceanic tsunami that traveled across the Pacific. Crescent City, California, situated over 2,500 kilometers (1,550 miles) south, experienced catastrophic harbor destruction due to bathymetric focusing across the Mendocino Fracture Zone.

The harbor was struck by four primary wave crests spaced roughly 40 minutes apart. The first three waves caused substantial flooding, but the fourth wave was the largest, measuring over 6 meters (20 feet) in height. The surge lifted docks off pilings, broke vessels free from moorings, and deposited large fishing trawlers into city streets.

Sixteen commercial vessels were sunk directly in the basin, while dozens were crushed against harbor rock jetties. Those who attempted to enter the harbor between the second and third waves to save their boats were caught by the fourth surge, resulting in numerous maritime fatalities.

The magnitude 9.1 Tohoku earthquake on March 11, 2011, generated a massive local tsunami along the Sanriku coast of Japan, alongside destructive trans-Pacific surges. In Kamaishi, Japan, the world's deepest tsunami breakwater failed to stop the immense wave energy. Inside the commercial port, large cargo freighters were lifted over seawalls and deposited inland into urban neighborhoods. Conversely, vessels operated by the Japan Coast Guard that immediately stood out to sea beyond the 200-meter (656-foot) depth contour rode over the tsunami waves with zero damage or hull stress.

Across the Pacific Ocean in Santa Cruz, California, 8,000 kilometers (5,000 miles) away, the tsunami arrived 10 hours after the earthquake. Harbor resonance triggered violent water surges oscillating at 15-minute intervals. Currents inside the narrow entrance channel exceeded 12 knots (22 kilometers per hour or 14 miles per hour). The surges tore 18 commercial docks from their moorings, sank 15 vessels, and damaged approximately 100 others, causing over 28 million dollars in maritime infrastructure losses in a harbor that was thousands of kilometers away from the seismic epicenter.

On December 26, 2004, a magnitude 9.1 megathrust earthquake ruptured off northern Sumatra. In coastal resort harbors throughout Phuket, Thailand, and southern Sri Lanka, vessels tied to docks or anchored in shallow bays were pulverized. Liveaboard dive boats operating in deep offshore waters near the Similan Islands experienced the wave only as a slight vertical swell followed by unusual surface water ripples. The crew only became aware of the catastrophe when they attempted to contact shore bases and observed terrestrial debris fields drifting out to sea.

Decision Matrix: Evacuate On Foot vs Transit Offshore¶

When a tsunami alert is issued, vessel owners and commercial operators face a life-or-death choice: should you take the vessel out to sea, or should you abandon the vessel and evacuate inland on foot?

This decision must be made using a strict, objective assessment of water depth, transit time, and harbor entrance geometry:

flowchart TD
    A["Tsunami Alert Triggered"] --> B{"Is Your Vessel Moored at a Dock or Marina?"}
    B -- "Io" --> C{"Time to Impact >= 2 Hours AND Open Channel?"}
    C -- "No: Less Than 2 Hours" --> D["DO NOT ATTEMPT TO MOTOR OUT"]
    D --> E["Tie Emergency Spring Lines If Time Permits (2 mins max)"]
    E --> F["Abandon Boat: Sprint Inland and Uphill to Safe Elevation"]
    C -- "Yes: >= 2 Hours Warning" --> G{"Can You Reach 183m / 100 Fathoms Before Arrival?"}
    G -- "Sega" --> D
    G -- "Io" --> H["Motor Directly Offshore to Deep Water Beyond 100 Fathoms"]
    B -- "No: Vessel Underway" --> I{"Are You in Deep Water (>183m / 100 Fathoms)?"}
    I -- "Io" --> J["Stay in Deep Water; Steer Bow Into Swells"]
    I -- "No: Shallow Shelf" --> K{"Can You Clear Shallows Before First Wave?"}
    K -- "Io" --> H
    K -- "Sega" --> L["Head to Nearest Deep Cove or Beach Boat, Evacuate Uphill"]

The Golden Rule of Harbor Evacuation¶

If your vessel is tied to a dock, slip, or harbor mooring, and the estimated time of tsunami arrival is less than two hours, you must abandon the vessel immediately and evacuate on foot.

Do not attempt to ready the vessel, untie frozen lines, start cold engines, or steer through congested harbor channels. In every major tsunami event, mariners who died attempting to save their vessels were either trapped in their slips as water levels rose, crushed between boats and docks, or grounded in shallow harbor entrance channels during rapid drawdowns.

Criteria for Offshore Evacuation¶

You should attempt to pilot your vessel into deep water only if all of the following conditions are met simultaneously:

1. Official tsunami warnings confirm that the arrival of the first wave is more than two to three hours away (typical for distant or teletsunami events originating across the ocean basin).
2. Your vessel is completely operational, fully fueled, with engines warm and running without mechanical hesitation.
3. The harbor channel is completely clear of congestion, drawbridges are fully raised, and you can maintain a transit speed of at least 10 to 15 knots.
4. Bathymetric navigation charts confirm that your vessel can transit beyond the 100-fathom (183-meter or 600-foot) contour line at least 45 minutes before the predicted wave arrival time.
5. Port authority officials and the local Coast Guard have explicitly authorized outbound maritime traffic and have not closed the harbor entrance.

Port Authority, Marina Management, and Harbor Hardening¶

Maritime facility managers, harbor masters, and port authorities carry institutional responsibility for mitigating life safety hazards and infrastructure collapse before, during, and after a tsunami impact.

Standard operating procedures for commercial ports and marinas during a tsunami alert include structured protocol phases:

Phase 1: Immediate Clearing of Marine Docks (T-Minus Warning Window)¶

• Sound Pier Alarms and Order Immediate Evacuation: Activate public address systems, pier sirens, and VHF marine broadcast warnings ordering all boaters, commercial fishermen, and liveaboard residents to clear slips and piers immediately.
• Shut Off Marine Utilities: Manually isolate utility distribution feeds to all docks. Severing shore power feeds at the main terrestrial breaker panels prevents electrical fires and waterborne electrocution hazards when slips submerge. Shut down fuel pumping rectifiers, and close emergency valves at marine fuel storage tanks to prevent petroleum spills into the basin.
• Halt Inbound Ship Traffic: Harbor pilots and vessel traffic services must immediately suspend inbound vessel entries, directing container ships, oil tankers, and bulk carriers to offshore holding anchorages situated in waters deeper than 200 meters (656 feet).

Phase 2: Structural Hardening for Facilities¶

Marinas situated in active tsunami zones can implement engineering modifications to reduce structural failure during moderate surges:

• Taller Guide Pilings: Extend piling heights at least 4 to 6 meters (13 to 20 feet) above historical maximum storm surge levels. Installing piling caps with heavy steel retainers prevents docks from floating off the tops of pilings during unexpected vertical water swells.
• Heavy-Duty Piling Guides: Replace standard aluminum or plastic dock roller guides with reinforced ductile steel collar guides capable of withstanding lateral shear loads exceeding 50 kilonewtons.
• Breakaway Gangways: Install articulated gangways with mechanical breakaway pins on the dock side, so that when floating docks rise or tilt violently, gangways disconnect cleanly rather than buckling docks or ripping shore bulkheads.

Vessel Recovery, Re-Entry Protocols, and Navigation Hazards¶

The danger to mariners does not end when the initial tsunami surge passes. The post-tsunami marine environment remains hazardous for days, characterized by long-period seiche waves, destroyed aids to navigation, and dense fields of floating debris.

+----------------------------------------------------------------------------------------------------+
|                                  POST-TSUNAMI RE-ENTRY CHECKLIST                                   |
+----------------------------------------------------------------------------------------------------+
| [ ] Maintain offshore holding pattern until Port Authority issues an official All-Clear.           |
| [ ] Verify harbor entrance channel is hydrographically surveyed before attempting passage.         |
| [ ] Post a dedicated forward bow watch to identify submerged logs, containers, and debris.         |
| [ ] Transit at dead slow speed (<5 knots) to prevent hull impact with unlit obstructions.          |
| [ ] Do not rely on navigation buoys or channel markers; anchors and chains are likely displaced.   |
| [ ] Prepare emergency tow lines and confirm bilge pumps operate prior to entering shallow waters.  |
| [ ] Assume shore facilities lack electrical power, fuel delivery, and potable water hookups.       |
+----------------------------------------------------------------------------------------------------+

The Multi-Wave Hazard Window¶

Tsunamis are not single, isolated waves; they are a train of successive waves spanning 12 to 24 hours. The initial wave is rarely the largest. Secondary or tertiary crests, arriving hours after the initial impact, are frequently amplified by bathymetric resonance within harbor basins.

Vessels holding offshore must remain in deep water beyond the 100-fathom line until official all-clear advisories are transmitted across marine VHF Channel 16 by the Coast Guard or local port authorities. Returning to harbor prematurely has led to numerous fatal groundings and collisions with secondary surges.

Post-Impact Navigation Hazards¶

When port authorities finally grant permission for vessels to re-enter coastal waterways, mariners must travel with extreme caution:

• Displaced Navigation Buoys and Beacons: Tsunami surges rip multi-ton concrete sinkers and anchor chains across the sea floor. Lateral channel marker buoys, daybeacons, and lighted hazard markers are routinely displaced hundreds of meters into active channels or stripped away entirely. Do not rely on visual buoys; steer strictly using calibrated GPS chartplotters and forward-looking depth sounders.
• Shoaling and Channel Infilling: Tsunami backwash transports immense volumes of terrestrial soil, roadbed material, and beach sand into navigation channels. Harbor channels that previously maintained 10 meters (33 feet) of draft may be choked with silt bars reducing depths to less than 2 meters (6 feet).
• Derelict and Submerged Flotsam: Millions of metric tons of wreckage litter the water surface and water column. Submerged shipping containers floating flush with the surface, tangled mooring lines, submerged structural beams, and fuel tanks present catastrophic hull-breach hazards to fiberglass and aluminum vessels. Post a dedicated watchstander on the bow, reduce vessel speed below 5 knots, and maintain immediate readiness to reverse propulsion.

Maritime Emergency Communications and Coordination¶

Effective communication during a maritime tsunami emergency supports rapid vessel tracking, timely distribution of safety alerts, and coordinated offshore holding maneuvers.

Vessel operators must maintain disciplined telecommunications practices:

• VHF sala ni wasawasa 16 Vakabibi: Sala 16 (156.800 megahertz) sa ikoya na veimatanitu wasawasa leqa, taqomaki, kei na kaci vakawasoma. Me dau vakarorogo tiko ga. Me lekaleka ka vakamatanitu na taranisimisani, maroroya na gauna ni cagi me baleta na veikacivi ni leqa rerevaki ni bula (MAYDAY) kei na kakaburaki ni veitaqomaki totolo (TAQOMAKI).
• Cakacaka ni ivakarau ni vakatakilakilataki vakataki koya (AIS): Maroroya na nomu waqa Kalasi A se Kalasi B AIS transponder cakacaka ena veigauna kecega. Ena kovukovu kaukauwa se na levu ni dravusa e salavata mai kei na sunami ni volukila, e vakatara na AIS vei ira na waqa ni bisinisi voleka, na dauvakacaca ni Coast Guard, kei na veiqaravi ni veitosoyaki ni waqa me ra vakamuria na nomu itutu, totolo, kei na ulutaga, ka tarova na veivakacacani levu e baravi ena gauna ni veivakasavasavataki levu.
• Kaci digitaki digitaki (DSC): Vakadeitaka na nomu retio ni wasawasa VHF e semati ki na dua na ciqomi GPS gugumatua ka rejisita ena dua na naba ni veiqaravi ni talevoni veikauyaki ni wasawasa (MMSI) dodonu. Ena dua na leqa tubukoso bibi, vakayacora na button ni leqa damudamu e vakadewataka e dua na burst ni leqa digitaki vakataki koya e tiko kina na nomu waqa ni veitaratara dodonu kei na ituvaki ni leqa tubukoso vakadodonu ki na veivanua ni veivakabulai ni veivakabulai ni wasawasa ni yasana.
• Veitaratara ni setilaiti kei na EPIRBs: Me baleta na waqa era cakacaka ena taudaku ni VHF laini-ni-raica na vanua (vakatautauvatataki 30 ki na 50 na kilomita se 20 ki na 30 na maile mai na siteseni ni baravi), italai ni setilaiti, talevoni ni setilaiti, kei na 406-megahertz na itukutuku ni leqa tubukoso) nuitaki na sikinala ni leqa tubukoso ni vuravura raraba. Vakadeitaka na nomu batiri ni EPIRB kei na iuniti ni sereki ni hydrostatic era tiko ena loma ni nodra siga ni cakacaka vakadeitaki.

Sitivikiti ni veivuke taumada¶

Na bula mai na leqa tubukoso e wasawasa, na kena vakacacani na waqavuka, kei na kena vakacacani na waqavuka ena toba e dau vakavuna na mavoa bibi ni yago, na katakata ni yago, voleka ni luvu, kei na mavoa ni vakacacani. Ni ra sa musuki tani na waqa e baravi mai na veivalenibula vakavuniwai e baravi ka sega ni rawa ni ra rawata na veiqaravi vakavuniwai ni leqa tubukoso ni korolevu na veivanua ni waqavuka sa vakarusai, e dodonu me tiko vei ira na lewe ni waqa na kila, vuli, kei na iyaya e gadrevi me ra vakarautaka na veiqaravi vakavuniwai ni bystander torocake.

Na vakacavari ni veivuke raraba, vakadonui taumada, CPR, kei na veivakadeitaki ni defibrillator e taudaku vakataki koya ena veiqaravi tauyavutaki, me vaka na Kauveilatai Damudamu ni Amerika, St. Na vuli vakavuniwai ena liga e vakavulici iko ena sala mo qarava kina na cegu bibi ni wai masima, vakasavasavataka na sala ni cagi e vakataotaki, vakayacora na veivakabulabulataki balavu vei ira na vakaleqai ena luvu, vakamalumalumutaka na veitiki ni yago e vakayacori mai na veicoqacoqa kaukauwa ni waqa, vakayagataka na veivakabulabulataki ni salanidra ena ikarua ni veivakabulabulataki, era yaco yani na timi ni vakasaqaqara kei na veivueti.

Na taro e dau tarogi wasoma .¶

Vakadikevi na ivurevure¶

• Matanitu ni Veiliutaki ni Wasawasa kei na Cagi (NOAA) Valenivolavola ni Veivakasalataki ni Sunami (NTWC, Amerika): Na Veitaqomaki ni Sunami vei ira na Dausoko, iDusidusi ni Veilakoyaki ena Wai Titobu, kei na Veika e Vakayacori ena Wasawasa.
• Na Matabose ni Wasawasa ni Amerika (USCG, Amerika): Na iVola ni Veikauyaki kei na Veivakadikevi ni Waqa, na Veivakasalataki ni Veitaqomaki ena Wasawasa me baleta na Vakavakarau ki na Sunami, kei na Veidusimaki ni Veivakasavasavataki ena Waqavuka.
• Na vanua ni itukutuku ni cagilaba e vuravura raraba (ITIC, UNESCO / IOC): Na idusidusi ni veivakasalataki kei na kena vakalailaitaki na cagilaba e vuravura raraba, na mapetaki ni leqa e wasawasa, kei na veivakatarogi ni waqavuka ni oti na veika e yaco.
• Tabacakacaka ni Draki mai Japani (JMA, Japani): Na i Vakarau ni Vakasala ni Sunami e Wasawasa, Na Vakadidike ni Bula ena Wasawasa ena Baravi kei Sanriku, kei na i Vakarau ni Vakarautaki ni Waqa ena Wasawasa Titobu.
• Na Vakadidike ni Vanua e Kalifonia (CGS, Amerika): Na iVola ni Qito ni Veisaumi ni Sunami e Wasawasa, Na Veisau ni Rogo ni Wasawasa, kei na iDusidusi ni Vakaukauwataki ni Veika Vakaitaukei ni Wasawasa.
• Matabose ni Veiqaravi ni Leqa Tubukoso ni Matanitu (FEMA, Amerika): Na idusidusi ni tuvatuva ni veivakabulabulataki ni waqavuka kei na veivakabulabulataki ni Tsunami.

Na idusidusi veiwekani¶

• Taqomaki ni sunami kei na veivakasavasavataki ena baravi
• Na cagilaba kei na cagilaba vakasauri
• Ulu seiche kei na rorogo ni toba
• Megatsunami ni vakasucu gone kei na dro tani mai na waqa lalai
• Na wai kei na vortex ni wasawasa
• Na naba ni leqa tubukoso ena vanua