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

[MarkJ]

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

You are going to die from a whale hitting your boat so why worry about containers?

Actually the tea leaves moved.... Ummmmmm... You are going to hit an unlit ship at night.

[Steadman Uhlich]

How to DETECT a metal shipping container?

Easy….

See the photo below.
_____________________

OK, that was the humorous answer.

Want my serious answer?

I think there is only one thing that is practical, low cost, is found aboard every sailboat with sailors AND has proven itself over thousands of years to be useful to mariners:

"Mark 1 Eyeball."

Yes, keeping a good watch and periodically (e.g. every 15 minutes) scanning ahead of the boat with a good set of eyeballs and a good binocular CAN see things that might go bump. And, that scan should also be 360 degrees too, as there are things (ships) that might bump you from behind or the side too.

[robert sailor]

Originally Posted by Snowpetrel

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...

I'd be BS'ing you if I told you I remembered all the details. All I remember was that we sailed within about 100 feet of it. I only saw one corner and I remember it as being steel, no markings as the corner was only just above water. Next chance I get I'll talk to my Son about it as he may remember more details as he was getting lectured for taking us there.
I have hit logs several times, one was so big it stopped us dead while sailing at night. Next day dove in and had a look and all there was was a scrape in the bottom paint.

[zboss]

I'm mostly concerned about hitting dead heads in the ICW or in channels... either pilings that have lost the top or pilings that have come completely free. We passed a telephone pole floating in the water in the Bahamas just about a month ago, we avoided it but it got real close.

[St. Elsewhere]

Originally Posted by Cottontop

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 expect that the doors on containers are not water tight. They are likely to fill with water until they sink to position where trapped air, or buoyant freight, keeps them partially afloat.

[Tingum]

You are Not going to see it at night, period. Small chance of seeing it in the daylight. Odds are in your favor but there is always a chance, sorta like having a tree fall on you ashore. That doesn't keep you inside does it?

[St. Elsewhere]

Originally Posted by MarkJ

You are going to die from a whale hitting your boat so why worry about containers?

Actually the tea leaves moved.... Ummmmmm... You are going to hit an unlit ship at night.

MarkJ

What about hitting a storm? How are doing with the weather off the US East Coast? I hope that you are in a good spot.

[Don C L]

I don't think it's a stupid question but I think no one has an answer for it. Most of us have seen logs or telephone poles, and even if you are keeping a good watch in broad daylight, these things can pop up surprisingly quickly. Wouldn't it be great if shipping companies put a little AIS unit with a battery that would light up when it got wet in every container? It wouldn't add that much to the cost of the container all things considered. Of course each container would need antenna of a few feet to pop up too, and it would have to draw very little power to last a month or so, but maybe by then its position could have been recorded and tracked? Ok, ok, but in these days when you can buy a GPS for so cheap, it is not a totally crazy idea, is it?

[senormechanico]

How do you know if it would float upright?

[hoppy]

Originally Posted by MarkJ

You are going to die from a whale hitting your boat so why worry about containers?

Actually the tea leaves moved.... Ummmmmm... You are going to hit an unlit ship at night.

Forget about the whales, what about the reckless sleeping solo sailors mowing down crewed yachts innocently sailing along and keeping watch. It's a bit like "Christine" on the high seas out there

[bobnlesley]

"Want my serious answer? "Mark 1 Eyeball."
Yes, keeping a good watch and periodically (e.g. every 15 minutes) scanning ahead of the boat with a good set of eyeballs and a good binocular CAN see things that might go bump. And, that scan should also be 360 degrees too, as there are things (ships) that might bump you from behind or the side too."

Ships, even other yachts/boats fair enough, but floating containers and tree-trunks; only in your dreams? You're more likely to spot a mermaid or perhaps a kraken whilst you're conscientiously looking out.

Whilst maintaining a sensible day-time watch, we saw a floating container in the approaches to the Mediterranean Sea (about 40M west of Gibraltar) in 2005. It was dark-purple, floated with about 4-6" visible above the water's surface, wasn't weed/barnacle encrusted, so probably hadn't been floating out there for too long and on a bright, sunny, clear, light-winds day, it was about 15-20' off our port quarter before we saw it; if it'd been on the bow, we'd have hit it, no question. As for spotting one at night/in rough seas, then you've not got a prayer; as someone noted earlier "if it really worry's you that much, get a steel boat."

Trees are as bad/worse to see - though perhaps not so fatal? - We clunked four or maybe five palm-trees whilst off the coast and up the rivers in French Guiana and Suriname. They floated below the surface, so you heard the 'thump, clunk and bang' first, then saw the tree when it broached the surface astern of us for a few seconds, before sinking back into the silt-filled water.

I claim Lesley hit (and killed!) a baby whale too, but that's another story and she denies it anyway.

[MarkJ]

Originally Posted by St. Elsewhere

MarkJ

What about hitting a storm? How are doing with the weather off the US East Coast? I hope that you are in a good spot.

I am in New York city

Weather: Fine.
Sunset: Sensational
Price of Beer:

Photo: Tonight on 34th Street

[hoppy]

Originally Posted by MarkJ

I am in New York city

Weather: Fine.
Sunset: Sensational
Price of Beer:

Photo: Tonight on 34th Street

Looks like it must be pretty windy from the photo. 34th street has broached

[NoTies]

I've got close to half a million miles under my keel in various guises as a commercial seaman to a recreational one, so plenty of experience. I'm more concerned about me making a mistake that will sink the boat rather than a container doing the job for me. That being said, as a recreational sailor I am not often in container ship shipping lanes. Maybe best to ease your stress levels and sail in the South Pacific, not too busy and the kava helps take the worry away.

[RaymondR]

I seem to remember that when they first started to use containers they were allowed to be watertight and consequently remained afloat but that the standards to which they are now constructed requires them to flood and sink when immersed. However this would not work if say they were filled with goods of low weight which displaced a lot of volume.

I think if you ran into one there is a fair chance of glancing off however if you dropped onto one by way of wave action you could poke a pretty lerge hole in your boat.