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Breenme · 17-09-2015, 09:30

Background:
My wife and I are planning our early retirement (5-7yr) plan. We are just being introduced to sailing. I was never really a boat person even though I grew up on Long Island NY. My wife has been more exposed to the boating world but not as an owner.

I am surprise nothing has been mentioned about this. So my question, concern, curiosity is the risk to the cruisers being caught out in the ocean when a tsunami is moving from Chile to Hawaii? Sailboats only go so fast. It takes what? 2 1/2 to 3 weeks to cross from Galapagos to the Marquises Islands. is there enough time to get to safety on this crossing before the tsunami could reach you? Also lets say you were by Chile at this time. When a tsunami starts after an earthquake how safe you are on your boat in that area? Say in a marina or anchored or just a few miles away sailing in or away at the time of the earthquake?

Sadly(maybe not) this is not deterring me from my plans when thinking worse cases I can imagine. is that bad?

deckofficer · 17-09-2015, 09:42

I have no experience being in a tsunami wave so I'll just repeat what I learned at the maritime academy. First you will not outrun it, as it can cover the distance of the Pacific in 24 hours. The good news though if your in the path and in deep water you will be just fine. The wave gets large and destructive when it reaches shallow water.

**a64pilot** · 17-09-2015, 09:48

Nothing on the water can outrun a tsunami, but it's energy that is travelling at the speed of an airliner, not the water, and I believe a tsunami is essentially undetectable by a boat in the open ocean

Breenme · 17-09-2015, 11:08

Thanks. I figured nothing to bad being no one was talking about it. But wife worries more and would never believe me i I told her o big deal per say.

best to have an independent source with experience in this.

**JPA Cate** · 17-09-2015, 14:39

Well, we had a tsunami warning for between 1 and 3 am this morning. We are in B. Kuto at Isle des Pins in New Caledonia. If you bring it up on open CPN, you will see that we are on the west, and well protected by lots of geological and marine structure. We decided not to leave the anchorage. We slept through what was a non-event here. I must note that we have left other anchorages in the past to get to deep water and waited for the all clear.

Now, if Australia had had the 8.3 quake, we would definitely have sought out deeper water. Oz is close to us; there would be little time for it to lessen in strength, and there is little to block it coming from there. The threads of energy generated by the quake would have straight and easy access to us here. The direction of travel of the shock waves in relation to where you are anchored is an important factor in the decision.

However, on the open ocean, you would never notice it.

Ann

El Pinguino · 17-09-2015, 15:15

Quote:

Originally Posted by Breenme

Background:
My wife and I are planning our early retirement (5-7yr) plan. We are just being introduced to sailing. I was never really a boat person even though I grew up on Long Island NY. My wife has been more exposed to the boating world but not as an owner.

I am surprise nothing has been mentioned about this. So my question, concern, curiosity is the risk to the cruisers being caught out in the ocean when a tsunami is moving from Chile to Hawaii? Sailboats only go so fast. It takes what? 2 1/2 to 3 weeks to cross from Galapagos to the Marquises Islands. is there enough time to get to safety on this crossing before the tsunami could reach you? Also lets say you were by Chile at this time. When a tsunami starts after an earthquake how safe you are on your boat in that area? Say in a marina or anchored or just a few miles away sailing in or away at the time of the earthquake?

Sadly(maybe not) this is not deterring me from my plans when thinking worse cases I can imagine. is that bad?

If you are in a Chilean port in the vicinity of the epicentre life will get 'interesting'.... google Coquimbo or Iquique together with Tsunami and look at the pics. Or for a better idea of what a bad one looks like just google '2010 chile tsunami'
Offshore in deepwater no probs but if you are alongside when the Tsunami sirens go off best to abandon your boat and head for the hills...literally.

**Jim Cate** · 17-09-2015, 15:48

There were lots of amateur videos of the effects of tsunami in Japan after the Fukushima quake. Frankly, they were simply terrifying! And lots of moored and anchored yachts were lost or damaged in the Indonesian/Malaysian tsunami a few years back.

But offshore, even fairly close in, floating objects are not much affected.

Jim

**a64pilot** · 17-09-2015, 16:07

I was thinking weigh anchor and motor out would be better than trying to get ashore, but I guess that really depends on how far you have to go to get to deep water.
Maybe it's not smart of me, but in really bad weather or something like this, I want to be far off shore, to have some maneuvering room. I got caught in a really bad squall many years ago just outside of Tampa Bay in a 45' Sportfish, and was being beaten back towards shore, I lost considerable ground.

Sent from my iPad using Cruisers Sailing Forum

DumnMad · 17-09-2015, 16:30

When you are far away from the centre its like a sudden rise in tide level. No problem unless you are in an estuary or channel where tidal flow could suddenly change and sweep you into trouble.

**Don C L** · 17-09-2015, 16:55

If you are in deep water you'll likely feel nothing. If you are anchored you have to judge how fast you can get your boat to deep water vs. how fast you can get yourself to high ground ashore.

svlamorocha · 17-09-2015, 17:26

Quote:

Originally Posted by a64pilot

Nothing on the water can outrun a tsunami, but it's energy that is travelling at the speed of an airliner, not the water, and I believe a tsunami is essentially undetectable by a boat in the open ocean

+1. The speed in deep water is 524 knots; you can roughly calculate arrival time based on that.

The tsunami is not detectable if far away from the coast (say 20 miles) AND in deep water, so we were told when there was a tsunami warning in the Galapagos. I will never forget the nervousness pulling up the anchor at night to leave port to reach open/deep water because there was a tsunami on the way.

In the Pacific at least, tsunami warnings are one good reason to keep the VHF close you you and on all the time even when you go ashore!

DumnMad · 17-09-2015, 17:40

NZ is some 5,500 miles away from Chile - the waves 300mm to 500mm high, wave period around an hour or so. No big deal but in shallow estuaries with narrow entrances there is a sudden change in tide flow that could catch people out.
For areas where the tide range is normally 2m in a 12 hour cycle a 0.5m high tide cycle in 1 hour would create unexpectedly high current flows.

El Pinguino · 18-09-2015, 04:11

Quote:

Originally Posted by DumnMad

NZ is some 5,500 miles away from Chile - the waves 300mm to 500mm high, wave period around an hour or so. No big deal but in shallow estuaries with narrow entrances there is a sudden change in tide flow that could catch people out.
For areas where the tide range is normally 2m in a 12 hour cycle a 0.5m high tide cycle in 1 hour would create unexpectedly high current flows.

Dunno about that... most hereabouts probably don't recall the 1960 tsunami.... Tsunami hits Hawaii - May 23, 1960 - HISTORY.com
..and the more recent one offshore from Thailand did more than a little damage in Sri Lanka.

I've dodged a couple in recent years... the Iquique one last year ... had gone back to Anto a short while before. A yacht that I had been alongside in Iquique turned up in Anto soon after... I think they had a bit of a fright... everything closer inshore had ended up parked on the seawall.

My previous terremoto event was in Seno Aysen in April 2007...... we were almost on top of the epicentre in about 300 metres.... two major shocks about a minute apart... felt as if we had run aground on gravel.... the result was that the side of a mountain a few miles ahead fell into the Seno... a big wave ( a serious big wave etched in my memory forever) but not really a tsunami... only killed 13 but they were the only 13 in the area... salmonera workers. If we had got underweigh 30 minutes earlier that day we would have been brown bread as we would have been abeam of the slip.

In Chile if ashore or on your yacht alongside you *will* hear the alarms and in most cases putting to sea isn't an option....

Some pics from Seno Aysen... a breaking sea coming back down a gully, some slips alongside the yacht and some very lucky congrio fishermen, and the slip itself.... still smoking a few hours later

**atoll** · 18-09-2015, 04:22

I experienced first hand the boxing day tsunami in Thailand,we were about 2miles offshore in 15 meters of water off the island of koh lanta,we felt nothing apart from some swirling currents shortly after seeing the breaking waves on the shoreline.

boats anchored inshore in less than 7m of water hit the bottom and quite a few lost their masts as a result!

El Pinguino · 18-09-2015, 04:37

Quote:

Originally Posted by atoll

I experienced first hand the boxing day tsunami in Thailand,we were about 2miles offshore in 15 meters of water off the island of koh lanta,we felt nothing apart from some swirling currents shortly after seeing the breaking waves on the shoreline.

boats anchored inshore in less than 7m of water hit the bottom and quite a few lost their masts as a result!

That I think is a major issue.... even if your boat stays put...water she go away before she come back..... Where I had been in Iquique we had maybe 1 or 2 metres under the keel.... I think we would have hit the bottom with a bit of a thump