While we were at the docks in Pago Pago, American Samoa, we experienced how it is to face a tsunami threat and how complicated it is to foresee the impact it will have on your exact location. We are sharing this information so that others can learn from it, and perhaps it can help you decide what is the best course of action, if you are faced with a similar threat.
A little background information first. The Pacific Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. Roughly 90 percent of all earthquakes occur along the Ring of Fire, and the ring is dotted with 75 percent of all active volcanoes on earth.
American Samoa is located along the southwestern part on this ring, just north of the Tonga Trench.
We have in particular one source we use that alerts us if an earthquake has happened, and whether there is a tsunami threat from it. It is the Pacific Tsunami Warning Center located in Honolulu, Hawaii, which is part of the The National Oceanic and Atmospheric Administration (NOAA) Tsunami Program which serves under the UNESCO-IOC Tsunami Program.
There is several ways to sign up for notifications from them – all listed on this page. We have subscribed to their email service, and we also follow local weather services depending on where we are. On July 29th, 2025, an earthquake took place of the Russian coast, which we were alerted about.
We also received an alert from the Facebook page of the local weather service.
The earthquake was a significant one, of magnitude 8.8, which is considered a megathrust earthquake. It was the 6th largest earthquake ever recorded, so no wonder tsunami warnings went off across the entire Pacific.
The earthquake was located 136 kilometers offshore of Kamchatka, Russia. Our immediate reaction was that since this earthquake happened to the northwest of us, and we were located far away in a southeastern bay of an island located to the southeast of the epicenter, the impact would not be very serious.
We thought that the tsunami would probably not wrap around the island and enter the bay, but we quickly learned that was wrong. Tsunami waves can wrap around land masses, and can then impact the water flow in the bay. We also learned that we could not necessarily trust all of the reports from other locations, as the shape of the bay and the depth and how it gets shallower all impact how the tsunami waves will impact a location.
There is a local tsunami warning alert system on this island, which is a siren that alerts the population that it is time to go to higher grounds. Along all of the roads on the island, there are also signs that inform the population where to go.
American Samoa was hit by a pretty significant tsunami in September in 2009, which killed 34 people and destroyed a lot on the island. Therefore, the locals were on the alert quite fast, and we could tell that the island was preparing for an impact just a few hours away.
Tsunami alerts are categorized into four levels: Information Statement, Watch, Advisory, and Warning, each with different required actions.
The agonizing waiting time deciding on how the waves would impact us and deciding what to do was the worst. We spent most of the day watching updates from locations closer to the epicenter, reading the email updates we got from the Pacific Tsunami Warning Center, as well as sharing information with the other cruisers at the docks and at the anchorage right in the bay next to us.
So far, most of the messages had categorized the impact the waves would have on American Samoa to be between 0.3 – 1 meter, which meant that we were on and Advisory alert.
The captain found out that the tsunami waves would hit at approximately 21.30, which was very close to high tide. Even with a 0.3m surge at the dock we were at, this would be devastating. We only had about that kind of clearing to the top of the dock at high tide, and we had no way of knowing how accurate the forecast was.
Based on all of the information we had, and especially when we learned that the tsunami waves would reach us around high tide, the captain made the decision that we would leave the dock and head to deeper water. According to our research, as long as we were in deeper water than 50 meters, we would not feel an impact of a tsunami at sea. We quickly prepared the boat to leave, and left two hours before the scheduled arrival of the first wave.
The harbor master is also a source of information when there is a tsunami threat, and so far we had not heard anything from him. We did, however, hear him on the radio just as we were on our way out of the bay. He then advised that the boats docked in the bay should leave and head to deeper water. We were joined at sea by the 3 of the other 4 catamarans that were at the dock with us.
We decided that spending the full night at sea was probably the best choice, as there might be debris in the water, and we also did not know just how long the tsunami threat would remain. We settled in for 3 hours watches on each of us through the night, and put out just a little of our genoa sail and cruised back and forth at the south side of the island.
We had just gotten through quite rough weather for a few days at the docks with little sleep. We were not exactly excited to face a night at sea right after the sleepless nights, but were also very happy that the earthquake did not happen a day before, as the sea state outside the bay would have been much worse.
We had a WhatsApp group with fellow cruisers located in the bay, and we kept each other updated throughout the night. The boats that stayed behind at anchor in the bay sent reports of the waves that kept coming into the bay. They also reported that they at last had heard the siren watch system go off in the bay, which meant that the population took to higher grounds.
It turned out that the second and third waves were much bigger than the first wave. In a short time span, the boats at anchor experienced that the water rose 1 meter and immediately fell 3 meters. This created a lot of currents in the bay, and the boats did several 360 degree turns around their anchor. Considering that the bay is known for not having great holding, several of the boats were also at risk of dragging in the currents. Luckily, they all held on, and no boats dragged.
However, water flooded the nearby park and streets, and sent debris like trash cans, etc into the bay. There were also several docks which were damaged. One of the boats we know got into their dinghy to rescue a floating dock which was on its way to crash into their boat. They also helped clear other debris from the bay in the middle of the night.
The tsunami waves kept coming for hours, a total of 3-4 hours, there were still waves surging in and out of the bay. This was certainly new information to us. We were not aware just how long the threat could last.
The water came up about 1 meter at the docks, and right as expected around high tide. This meant that the water flooded the dock, and we would not have been in a good situation if we had stayed behind.
The owner of the catamaran next to where we had been at the dock, was standing with water up to her knees, pushing her boat off the docks during the surges. However, her boat weighs 25% of our boat, and we are not sure it would be possible for us to keep our boat from floating onto the dock in the surge.
When we entered the harbor the following morning, we saw quite a lot of debris in the water, so we were happy that we had not gone back into the bay in the dark. We also witnessed other signs how high the water had come, mostly dirt and debris on the streets, on the docks, etc.
We were quite surprised when we realized that the floating docks next to our concrete docks had not fared well in the surge. We thought the floating docks would handle the raise and lowering of the water quite well, but that was not the case. The outer part of the floating docks were stuck at the top of the poles. We suspect that the fast movement up and down of such a big water mass, was too abrupt for the docks to handle.
We were glad to learn that there was no big damage and nobody hurt from the tsunami on the island.
It was very special to meet the other cruisers again the next day, and share notes. After learning how complicated it is to predict the local impact a tsunami will have on where you are, we will probably head out to sea next time as well. The agonizing waiting time the boats at anchor had, must have been worse than the time we spent knowing we were safe at sea.
We have a newfound respect for keeping an eye out for these tsunami alerts, as we are now moving into a territory which sees earthquakes often. The long response time we experienced this time, might not be the situation the next time.
