Yacht hits container

[sighmoon]

So your boat has nothing below the water line ?

See me after class

The definition of floating means some of it is above the water though. The triangular bit you saw in post 3 was above the water right?

I am sure a submariner will be along shortly to explain that the achievement of neutral buoyancy can be a desirable, but almost impossible, physical state.

That's what I meant.

 

[Ricd]

...and conversely, especially in the winter months: the top metre or so of water is often quite a few degrees colder than that lower down, and hence less dense.

Colder sea water is more dense not less dense unless of course it is cold enough to freeze

 

[Evadne]

And then there is salinity, which is not as constant as some might assume. Ask anyone who's sailed on Loch Etive after a lot of rain.

Actually it's rare in the open sea to have such a narrow density layer at the surface. Storm waves in the north Atlantic can produce a mixed layer 100m thick, but in the absence of mixing seawater will increase in density with depth, for the depths we are talking about.
(There's a simple density profile shown here http://www.windows2universe.org/earth/Water/density.html many others available via google if you're really interested.)

 

[dt4134]

Colder sea water is more dense not less dense unless of course it is cold enough to freeze

Fresh water at least is most dense at 4 deg C, and I imagine sea water isn't too different. It's a peculiar characteristic of water, but is very handy for fish that can soak up the heat (at 4 degrees) at the bottom of frozen ponds.

 

[Ricd]

Fresh water at least is most dense at 4 deg C, and I imagine sea water isn't too different. It's a peculiar characteristic of water, but is very handy for fish that can soak up the heat (at 4 degrees) at the bottom of frozen ponds.

I did say sea water ..which due to its salinity lowers the maximum density to the freezing point at roughly -2 deg C at which point the fresh water freezes out and the less dense salt free ice floats. The residual salt from the ice forming dissolves in surface layer of water upon which the ice is floating, increasing its density and causing it to sink...so sea water is quite different to fresh water. water.

 

[KellysEye]

>>A container will fill with water and sink unless it's full of anything that gives the whole package a density of less than 1. Waterproof, they are not!

If they weren't waterproof think of the damage done to the contents in rain and spray.

>Floating just below the surface" is an oxymoron

I don't know the physics behind it but they are just below the surface hence you can't see them in daylight. If you could see them few would hit them if keeping a good watch. We had the same problem with logs 120 miles off Grenada after a hurricane.

I don't think a container would sink a steel boat. We saw a steel boat in the Canaries that had been hit by the bow bulb of a ship, the steel had stretched to a large bowl shape which destroyed a lot of internal furniture.

 

[Reverend Ludd]

The definition of floating means some of it is above the water though. The triangular bit you saw in post 3 was above the water right?

Indeed

 

[2Tizwoz]

Partially submerged container.

Not difficult to fill it with cargo so it floats a bit lower in the water.

Trees are probably far more common.

 

[macd]

Colder sea water is more dense not less dense unless of course it is cold enough to freeze

So just which bit of what I wrote is inconsistent with that? And as dt4134 wrote, the relevant temperature is 4C not 'cold enough to freeze" (mind you he seems predisposed to the number '4', so may be biased). It's all to do with hydrogen tetrahedrals, apparently.

 

[onesea]

Partially submerged container.

Not difficult to fill it with cargo so it floats a bit lower in the water.

Trees are probably far more common.

My 2 pence worth agree with the guy who said, neutral buoyancy ask submariner (I am not one) answer almost certainly, not likely...

Containers, unlikely to hover below the surface. Also unlikely to float as shown above surface... Well not for long, containers should be weather tight, they do not need to be fully water tight (Do they not need to be able to let hot air out in tropics and cold air in in Europe?).

Any one ever in history (years ago of course before we became environmentalists) tried sinking a beer can when they had finished it?

Unless you get rid of EVERY LAST BIT OF AIR it will float just on surface.. Maybe a millimeter or less of free-board...

Is that not like a container (Or most things thrown it the sea)? Some will have more dense stuff in and some less dense stuff... So SOME might float and SOME might sink, in the middle there is allot of space for lot of containers to be bobbing around with minimal free-board... Until they get rid of the last bit of air or land up on the coast?

Just like logs shown that gradually become more waterlogged and float lower and lower until that last small branch...

I am sure water density and salinity will have some effect, so will sea and swell or lack of it for visibility to see it...

Try taking up the fight with the company that builds a $120 Million ship (plus minus a bit), then looks to employ seafarers on as lower wage as possible to crew it. To put lights/ trackers on containers they do not own to protect cargo that is not there's. Its just there responsibility to carry, if they are following the rules why should they? All they want to do is see profits go up (like any other company).

As for the risks, if its a major concern to you start the campaign to stop the containers going over the side, or give them lights or what ever else, you will get support.

The sea has always be a dangerous place, the hazards change but the sea does not. If you want low risk and worry do not buy a beach hut, its known to take them occasionally

 

[Kelpie]

They must sink eventually; we get most types of detritus washing up on the west side of the Hebrides but I have never heard of a shipping container being found.