Avoiding coastal surf? How do you do it?

[Franziska]

So, I do apologize sincerely. After all there is a symbol. Visible only when you are very very zoomed in and probably already amidst of it.
So I guess I will from now on always run two displays. One really zoomed in a lot and one overview.
Wasn't there a reef hit by a Volvo which had a similar background [emoji3]

[boatman61]

If you zoom in onthe chart you will see Nazare Canyon.. a deep cut through the shallows to the N and S.. this is what contributes to the massive surf one sees there.
If you want to go into Nazere come in from S of the canyon.. 3 to 5nm will see you past without trouble.. also the pass between Peniche and Islas Berlingas is pretty straightforwards.. even at night.

[mikereed100]

Ocean swells will start to break when the depth is 1.3x the height of the swell. In other words, a 10' swell will start to break in 13' of water. Surf spots follow these same rules. There are areas where the swell is focused due to the bottom contour, but if you use common sense you will stay out of trouble. Often charts will indicate areas of 'breakers' where a contrary current causes the waves to break in deeper water, or where shoaling can cause shallower depths than shown on the chart, but surf spots are really no different from any other part of the coastline.

[Aqualibrium]

As an old Scottish Captain said
“It’s not the sea that sinks ships laddie, it’s the land, the bluddy land!!!!!!”

[Don C L]

You probably got the info you need, but around these parts we have some popular surf spots and most of them are so close to shore no one would think to be sailing in that close. One famous spot at Pillar Point just south of San Francisco (Mavericks) is a little farther offshore in about 20 feet of water, and it’s possible someone unfamiliar with the area might think to cut in close to the point there. In that case the chart does mention “outer breakers.” The bad news is that places like those can be sneaky and unforgiving to anyone who goes there during a lull in the wave sets, the good news is places like those are relatively small areas, easy to see when breaking (unless there is fog) and easy to avoid.

[Franziska]

Hey Don,

those are exactly the ones which can cause trouble, especially if you are far from your own neck of the woods and without enough local knowledge.
Btw. Is that the infamous potato patch you refer to?

Learned a lot here + one really needs to go into details when planning.

Regarding charts its so easy to miss something when not fully zoomed in.

[Don C L]

Yeah there’s not one “potato patch.” AFAIK That is a general term for a location where waves, currents, a point of land or steep cliffs all conspire to create a jumbled disorganized collection of steep waves locally. Around here Point Conception gets it, San Francisco Bay entrance gets it, west end of Santa Cruz Island here gets it, I am sure there are many more around the world. Typically those are not going to be surfing spots though, though they might be near them.
Btw, when places like Mavericks are breaking, there are folks who go out to get a view of it and they hover around just outside to try to get photos of it. Can be a tad risky for those who want the best shots.

[SoFloLandSea]

“Out of sight of land the sailor feels safe. It is the beach that worries him.”
– Charles C. Davis

Keep your ears open.

[barnakiel]

There is nothing there for you. Charts show you the depth. What else would you expect?

Info like this you will find in sailing directions.

Do you know what sailing directions is?

You are not supposed to be on this coast nowhere from Vigo to Sao Vincente.

BTW The surfing surf video, skip it. It is not as impressive close up. The cameraperson did a good job though.

BTW Look up CM93 for THE CANYON. The Nazare underwater canyon. Most "sailors" sail by unaware.

b.

[AiniA]

Completely different part of the world but our only experience with coastal surf was at anchor off Easter Island. The image below shows the situation except that the surf breaks on either side are much closer together than shown. In normal conditions you can get through fine but you can talk to the surfers on either side in a normal voice. Sometimes the surf joins up and you are stranded either onboard or onshore. The day we were leaving we had to get one of the dive boats to tow us out since our 6 hp outboard was not up to it I thought - and didn't want to find out.

[Dockhead]

Originally Posted by mikereed100

Ocean swells will start to break when the depth is 1.3x the height of the swell. In other words, a 10' swell will start to break in 13' of water. Surf spots follow these same rules. There are areas where the swell is focused due to the bottom contour, but if you use common sense you will stay out of trouble. Often charts will indicate areas of 'breakers' where a contrary current causes the waves to break in deeper water, or where shoaling can cause shallower depths than shown on the chart, but surf spots are really no different from any other part of the coastline.

Exactly.


Charts may show areas with unusual water turbulence -- usually those caused by currents or tide, but sometimes you see markings for turbulence caused by underwater features.


But they don't, not ever in my experience, show ordinary surf which is just a function of shallow water. Mariners just know where that will occur, and no one has any business navigating that close to shore.


Turbulence -- especially, tidal rips or tide races -- are hugely magnified by wind against tide situations, and even a small amount of wind can set off a huge turbulence which can be dangerous, in a big enough tidal race.


The Faroe Islands have some gnarly tidal races, something like what you find in the Channel Islands, except the Faroes have a lot more narrow channels between the islands. There is an old tidal atlas which everyone uses there which shows the races as "red fans of death". In the preface to the atlas is this little story:

[hpeer]

Originally Posted by Franziska

So, I do apologize sincerely. After all there is a symbol. Visible only when you are very very zoomed in and probably already amidst of it.
So I guess I will from now on always run two displays. One really zoomed in a lot and one overview.
Wasn't there a reef hit by a Volvo which had a similar background [emoji3] Attachment 175822

Just for kicks and giggles take a look at a standard government issue chart, can be a raster electronic version, and ask yourself if you would have had the same problem with them.

And yes there was a similar problem with a race boat hitting a reef, and many more examples of folks not zooming in adequately. It seems to be much worse on vector charts than on raster charts, which are the same as paper charts.

[Paul Elliott]

Generally, looking at the charts should give you a clue, but they aren't always marked "waves".

Here's Cortes Bank, about 100 miles off the California / Mexico border. It occasionally has some of the largest surf in the world. Other times it looks like a lake.

[Dockhead]

Originally Posted by Paul Elliott

Generally, looking at the charts should give you a clue, but they aren't always marked "waves".

In other words, don't count on warnings marked on the chart.


But this is a trivial problem. You will not find surf -- as opposed to current-driven turbulence -- in water deeper than 1.3x the swell height, so in 30 meters of water or more, you can forget about it, unless there is some kind of dramatic underwater feature.



Stay off the coast ("Coasts are not for hugging!") and watch the chart for undersea mounts and canyons, and you can forget about simple non-current driven surf.


It's current-driven turbulence which is the real issue, and that is often marked on charts, but not always, and that takes more study to recognize and predict. Avoid tidal rips and especially in wind against tide situations.


Waves also break because of the interaction of separate wave trains. But that is also a part of ocean sailing, to understand and recognize when you may encounter such conditions.

[waterman46]

Originally Posted by Franziska

Hey, just happened to look at the port of Nazare in Portugal on a set of Cm93 charts.
As it goes I know that North to the lighthouse there is a world famous surfspot.
Great for surf pros, surely not for a sailboat hugging the coast.

On the charts there seems to be no indication to this.
So I am thinking, if I am completely new to an area and do not know about this and have only charts, how do I avoid getting accidentally into something like this?

I know that it's prudent to keep a distance from shore. Still wondering though why there are no indications on the charts....

Yes there is an indication on any chart, of area to be avoided in big swell conditions. Its called the depth of water as shown on the chart. And always always set an alarm on your depth gauge. You don't want to be in water that is less than about 5x the height of the open ocean swells. That's about the depth at which the swell starts to noticeably steepen.

I have seen the notation "Breaks" on many charts, and those are the spots that are notorious for breaking surf.