how to detect CONTAINER lost at sea and NOT hit it?

[alexxx]

i know, guys, this might sound like a stupid question, but being in the process of learning everything i can about sailing and navigating , i'd like to cover that question.
It happened recently again, near Madeira, a sailboat hit a cargo container floating under the surface, and the boat almost sank.
How can you safely detect these things? is there a sonar or other equipment one can install on the sailboat with an alarm so one has enough warning time to change course?
thanks guys (and girls)
alexxx

[tayana55]

Originally Posted by alexxx

i know, guys, this might sound like a stupid question, but being in the process of learning everything i can about sailing and navigating , i'd like to cover that question.
It happened recently again, near Madeira, a sailboat hit a cargo container floating under the surface, and the boat almost sank.
How can you safely detect these things? is there a sonar or other equipment one can install on the sailboat with an alarm so one has enough warning time to change course?
thanks guys (and girls)
alexxx

Original mark one eyeball is best, electronic gadgets for yachts aren't advanced enough to detect partially submerged objects. Forward looking sonar will give you short warning, maybe, maybe not. You'll have seconds to take avoiding action if and when the alarm goes off.

[ontherocks83]

only just be ready to react with sufficient dewatering pumps and an emergency sop for what to do if it should happen. Sailing is a risk whether on the ocean or lakes bad things can happen and sometimes there is nothing you can do to prevent it

[secrabtree]

I'm not sure that a container just below the surface can often be detected, and even one that is awash can't be detected at night. At least that is my belief. I've never seen on. But maybe I've never been near one.
I am not as afraid of my bow hitting one that is barely awash or below the surface. I think my bow would just ride up on it. The reason for that belief is that a week ago, while coming into the marina my transmission linkage failed. I hit the dock so hard that I ran up on it and my bow was a couple feet beyond the other side of the 5 foot wide dock that was about a foot above the water. But if my bow was just here it would miss the container and the container contact the side of the boat, would the corner of the container rip a hole in my topsides? Probably. That judgement is based upon a recent movie staring Robert Redford, "All Is Lost". In making that movie the studio sank THREE Cal 39's just like mine!

[laika]

You could reinforce the leading edge with some kevlar cloth.

[boden36]

If this really worries you , consider a steel yacht. Not infallible but much stronger than plastic or wood.

Regards,
Richard.

[Snowpetrel]

Any link to the report? Having spent years working on container ships and not losing one box always makes me sceptical of claims like this. I've hit a Whale, a lot of ice and a few logs at sea, but have never even seen a container floating about. Anyone got a confirmed sighting of one? Anyway. To the op's concern. I like to make the bulkheads under the forward berth into half height watertight compartments. It would at least give me a fighting chance to find and contain any damage.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

[cal40john]

Originally Posted by Snowpetrel

Any link to the report? Having spent years working on container ships and not losing one box always makes me sceptical of claims like this. I've hit a Whale, a lot of ice and a few logs at sea, but have never even seen a container floating about. Anyone got a confirmed sighting of one? Anyway. To the op's concern. I like to make the bulkheads under the forward berth into half height watertight compartments. It would at least give me a fighting chance to find and contain any damage.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

Are you talking about losing containers or sailboats hitting containers?

These reports seem to say 300-500 per year excluding catastrophic events:
Busting Ocean Myths: How many containers are really lost at sea? | Southern Fried Science

http://www.worldshipping.org/industr...l_for_Dist.pdf

This article has a couple of sailboat hits and near miss reports:
A legendary offshore danger - Ocean Navigator - March/April 2013

[El Pinguino]

Originally Posted by Snowpetrel

Any link to the report? Having spent years working on container ships and not losing one box always makes me sceptical of claims like this. I've hit a Whale, a lot of ice and a few logs at sea, but have never even seen a container floating about. Anyone got a confirmed sighting of one? Anyway. To the op's concern. I like to make the bulkheads under the forward berth into half height watertight compartments. It would at least give me a fighting chance to find and contain any damage.

Ditto, but I have yet to hit a whale... so I'll see your whale and raise you a bit of Terra.....
Did see a palm tree in central Bass Strait once with one very black and lonely frond raised forlornly aloft...
Securing as you suggest below the frd bunks and and maybe under the saloon side benches makes sense to me ... if you really worry about such stuff.

[robert sailor]

Originally Posted by Snowpetrel

Any link to the report? Having spent years working on container ships and not losing one box always makes me sceptical of claims like this. I've hit a Whale, a lot of ice and a few logs at sea, but have never even seen a container floating about. Anyone got a confirmed sighting of one? Anyway. To the op's concern. I like to make the bulkheads under the forward berth into half height watertight compartments. It would at least give me a fighting chance to find and contain any damage.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

Actually did see one or what was left of it floating a few inches above the water coming back from Hawaii 30 years ago. My young Son was driving and altered course to look at a some birds sitting on it. I was below and noticed the compass showing us altering course and came up just in time to change course. Somewhere in the deep reaches of my mind I still have a little worry about hitting something at sea.

[Snowpetrel]

Originally Posted by robert sailor

Actually did see one or what was left of it floating a few inches above the water coming back from Hawaii 30 years ago.

Very interesting report Robert, thanks for that. Was it a positive ID or a suspected box shaped item that might have been a container. Ie Did you see the corner castings, or company markings. Also how much weed was growing on it, and was it in one piece.

The whale we hit sure made a bang. If we hadn't seen it astern (and lots of brown blood) we would have thought it was something harder. We were surfing under kite at about 15 knots at the time in about 30 knots of wind mid Tasman in a lightweight plywood 45footer. Amazingly no damage at all! Good job they've got nice soft blubber...

[K_V_B]

Originally Posted by cal40john

These reports seem to say 300-500 per year excluding catastrophic events:
Busting Ocean Myths: How many containers are really lost at sea? | Southern Fried Science

300 to 500 a year. So the chance of actually hitting one is almost negligible. I would not worry to much about hitting containers.

[Cottontop]

And I suppose many of those lost sink over time.

[Hudson Force]

We did see a shipping container grounded on the windard side of Elliott Key south of Miami, Florida about ten years ago.

[Cottontop]

And just thinking about this a little more.

A typical container in the U.S. Is 40'x8'x8'. That's a displacement of about 160,000 pounds of water. I suppose the average container hauled by a truck, at least, does not contain much more than 40,000 pounds. So it should float very high. (Hope I got the math right)

I suspect the dreaded container awash, with just a couple of inches above the water, is a rare thing indeed.