• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

Eerily Calm Sea

GNC

King-Sized Canary
Joined
Aug 25, 2001
Messages
33,634
Could someone refresh my memory, please? I read ages ago an account of a sailor, possibly crossing the Atlantic solo, who amidst the choppy seas found himself sailing through a large patch of ocean that was eerily calm and still, not even a ripple. Does this ring any bells for anyone? Could you identify it? Thanks.
 
Could someone refresh my memory, please? I read ages ago an account of a sailor, possibly crossing the Atlantic solo, who amidst the choppy seas found himself sailing through a large patch of ocean that was eerily calm and still, not even a ripple. Does this ring any bells for anyone? Could you identify it? Thanks.
The Rime of the Ancient Mariner?
 
Could someone refresh my memory, please? I read ages ago an account of a sailor, possibly crossing the Atlantic solo, who amidst the choppy seas found himself sailing through a large patch of ocean that was eerily calm and still, not even a ripple. Does this ring any bells for anyone? Could you identify it? Thanks.

Over the years I've seen multiple references to surprisingly calm seas in the North Atlantic, some of which were in reference to transatlantic sailors and rowers. If I recall correctly, such 'flat' sea is most commonly encountered between northern North America and northern Europe, inside the circular course of the Gulf Stream.
 
Sargasso Sea?

Though it's probably full of floating plastic bottles and trainers with feet in by now.

Could have been, but in my memory of the story it was a patch of about a hundred metres across.
 
Over the years I've seen multiple references to surprisingly calm seas in the North Atlantic, some of which were in reference to transatlantic sailors and rowers. If I recall correctly, such 'flat' sea is most commonly encountered between northern North America and northern Europe, inside the circular course of the Gulf Stream.

Maybe it's a common tale, but this guy seemed to be surprised by it, no wind, no waves, nothing but still water.
 
Years ago, I went on a cruise between Galveston and Cozumel. It was the height of summer.
The sea was so still, it was almost like a mill pond. No waves at all. Thankfully, we weren't in a sailboat.
 
This is starting to sound normal sea behaviour rather than an anomaly.
 
There are huge waves in deep oceans which never break the surface. If they reach high enough they can sink ships in seconds. Seas can look calm on the surface but be moving about wildly underneath.
 
There's The Doldrums or Inter-Tropical Convergence Zone, as described in The Ancient Mariner

a belt around the Earth extending approximately five degrees north and south of the equator.

which lead on to Horse Latitudes

According to legend, the term comes from ships sailing to the New World that would often become stalled for days or even weeks when they encountered areas of high pressure and calm winds. Many of these ships carried horses to the Americas as part of their cargo. Unable to sail and resupply due to lack of wind, crews often ran out of drinking water. To conserve scarce water, sailors on these ships would sometimes throw the horses they were transporting overboard. Thus, the phrase 'horse latitudes' was born.

Would make a great name for a band.
 
Only live a short distance from the sea and you do get days when it's absolutely flat not a ripple in sight,
some days it is clear to and you can see down to the sea bed quite a long way down, ships pass about
3 or 4 miles out and it is surprising how big the wash is from them the ship will be out of sight before
the wave hits so you think "were did that come from.
 
Could someone refresh my memory, please? I read ages ago an account of a sailor, possibly crossing the Atlantic solo, who amidst the choppy seas found himself sailing through a large patch of ocean that was eerily calm and still, not even a ripple. Does this ring any bells for anyone? Could you identify it? Thanks.

I don't know the reference but I should think he was talking about the Sargasso Sea - I've been through it quite a few times and it's a lovely stretch of calm sea off the east cost of North America.
https://en.wikipedia.org/wiki/Sargasso_Sea
 
Only live a short distance from the sea and you do get days when it's absolutely flat not a ripple in sight,
some days it is clear to and you can see down to the sea bed quite a long way down, ships pass about
3 or 4 miles out and it is surprising how big the wash is from them the ship will be out of sight before
the wave hits so you think "were did that come from.
I've seen the same sea in those circs RaM. Actually looks quite weird, when you're used to waves crashing against the shore sometimes.
 
I'm neither a physicist nor an oceanographer (Jim), but I seem to recall the idea of constructive and destructive interference, whereby sets of waves that meet can reinforce each other creating more powerful waves or effectively cancel each other out (and one another in weird multi-wave collisions?).

Could climactic and geographic factors bring about a major area of destructive interference.

Here, for instance:

Destructive interference
Destructive interference occurs when waves come together in such a way that they completely cancel each other out. When two waves interfere destructively, they must have the same amplitude in opposite directions. When there are more than two waves interfering the situation is a little more complicated; the net result, though, is that they all combine in some way to produce zero amplitude. In general, whenever a number of waves come together the interference will not be completely constructive or completely destructive, but somewhere in between. It usually requires just the right conditions to get interference that is completely constructive or completely destructive.

Source:
http://physics.bu.edu/~duffy/py105/WaveInterference.html
 
I'm neither a physicist nor an oceanographer (Jim), but I seem to recall the idea of constructive and destructive interference, whereby sets of waves that meet can reinforce each other creating more powerful waves or effectively cancel each other out (and one another in weird multi-wave collisions?).

Could climactic and geographic factors bring about a major area of destructive interference.

Here, for instance:

This is not what I was referring to about, but it's in the same conceptual zone.

A 'Cross Swell' is created in some circumstances when two 'sets' of waves interact at right-angles to each another:

xail3tjd0l521.jpg


Ile de Ré cross section where two currents meet.
 
This is not what I was referring to about, but it's in the same conceptual zone.

A 'Cross Swell' is created in some circumstances when two 'sets' of waves interact at right-angles to each another:

View attachment 13714
Lieutenant Worf : It is the sign of LaForge. It is a message to travelers. It is said when these lines appear and disappear in a pool of water, the road ahead will be filled with good fortune.
 
I'm neither a physicist nor an oceanographer (Jim), but I seem to recall the idea of constructive and destructive interference, whereby sets of waves that meet can reinforce each other creating more powerful waves or effectively cancel each other out (and one another in weird multi-wave collisions?).

Could climactic and geographic factors bring about a major area of destructive interference.

Yes and no. (Go not to myself for advice for I will say both no and yes.)

Destructive interference is a simple concept. Two sets of waves cancel each other out when they are the same wavelength, and the troughs of one set match the peaks of the other, and vice versa. This is the principle used in noise cancelling headphones.

It s theoretically possible for two natural sets of ocean waves exactly to cancel each other out. However, it would require freak conditions and in practice, is most unlikely, and if it happened at all, it would be on a small area.

Waves on the ocean are seldom straight lines. The wind blows in one area and the waves radiate from the wind. From their point of origin, waves gradually grow in size as they absorb more energy from the wind, then they gradually decrease in size once they are away from the wind and they start to lose energy. The wind itself is never uniform in strength.

When waves hit shallows or pass near to the shore, they bend towards the obstruction. (This can be fascinating to watch at Lulworth Cove, for example. Waves enter through a narrow gap between headlands and they curve so that they break uniformly along a semicircular beach. (Concave curve.))

Thus, two sets of naturally formed waves could interact to cancel each other out, but as they would both be curved, the area of perfect cancellation would be small.

The surface of the sea is a chaotic system: everything is governed by cause and effect, but small irregularities in the cause (gusts of wind) and the effect (waves interacting) mean that exactly what happens at any point and time cannot be predicted. Stand on a Cornish headland and you will see an obvious rhythm to the waves, but watch each one closely and you will see that they break differently, and the force with which each wave hits the rocks will depend on how much it is undercut by the backwash of the previous one.
 
(This can be fascinating to watch at Lulworth Cove, for example. Waves enter through a narrow gap between headlands and they curve so that they break uniformly along a semicircular beach. (Concave curve.))
I've watched that myself, it's quite nice to see.
 
I'm neither a physicist nor an oceanographer (Jim), but I seem to recall the idea of constructive and destructive interference, whereby sets of waves that meet can reinforce each other creating more powerful waves or effectively cancel each other out (and one another in weird multi-wave collisions?).

Could climactic and geographic factors bring about a major area of destructive interference.

Here, for instance:
They can even be made to stand still in an constructive manner. The phenomena is called standing waves in which case the magnitude of the wave can be doubled and appear to stand still. It takes just the right conditions for this to happen. It can even be demonstrated with a simple piece of string and a source of agitation.
 
Back
Top