# A couple of questions about sea mines. **URL:** \ **Category:** Factual Questions\ **Created:** [July 6, 2014, 2:02am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456 "2014-07-06T02:02:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [July 6, 2014, 2:02am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/1 "2014-07-06T02:02:38Z")
You know, [these guys.](https://www.google.com/search?safe=off&site=&tbm=isch&source=hp&biw=1024&bih=643&q=sea+mines+still+active&oq=sea+mines&gs_l=img.1.1.0l5j0i5l5.2195.7927.0.12165.9.9.0.0.0.0.306.1370.0j8j0j1.9.0.chm_loc%2Chmss2%3Dfalse%2Chms2min%3D10%2Chms2max%3D10%2Chmtb%3D120%2Chmta%3D1440%2Chmrde%3D0-0%2Chmde%3D1-0%2Chmmpp1%3D1-0%2Chmmpp2%3D1-0%2Chmffs%3D10000...0...1.1.48.img..0.9.1334.9mf1s7MUPwM&gws_rd=ssl#q=sea%20mines&safe=off&tbm=isch) Are there any currently active minefields at sea? How did they know, after WWII, that they had all been successfully removed? ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 6, 2014, 2:30am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/2 "2014-07-06T02:30:21Z")
Yes, there are, especially around the DMZ in the Koreas. How do you know? Minesweepers go through and cut mooring lines so some ‘float’ to the top for evental EOD rendering-safe and disposal. Otherwise, you’re sending EOD divers into the water. Sometimes, metallic/magnetic signatures can point you in the direction of one. But then again, you need to dispose of it. How’d they know after WWII? No more sunken ships. Tripler There’s modern mines that lay in wait for _years_ until ‘activated.’ ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [July 6, 2014, 2:54am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/3 "2014-07-06T02:54:47Z")
> [@Tripler](#): > > How’d they know after WWII? No more sunken ships. > > Tripler > ’ Coming from you, that is particularly hilarious. BOOM! Shit, we missed one. :o ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [July 6, 2014, 3:24am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/4 "2014-07-06T03:24:52Z")
On the first page of images for WW2 sea mines, you get this picture: [http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg](http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg) You really have to give those guys back in World War II credit for being masters of camouflage. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [July 6, 2014, 3:45am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/5 "2014-07-06T03:45:44Z")
> [@chacoguy](#): > > How did they know, after WWII, that they had all been successfully removed? They weren’t all successfully removed. A quick google search found that they’ve found some as recently as 2012, when two WWII sea mines were found in the Ems River estuary (I have no idea where that is…). There are areas marked on nautical navigation maps that warn of known WWII unexploded ordnance. All sorts of things from WWII including sea mines, land mines, bombs, shells, and chemical weapons, are all still a hazard even today. The chemical weapons can be particularly nasty since the casings are so old that they are often rusting through and the dangerous chemicals can leak out and cause harm. A lot of that stuff was dumped into the ocean to dispose of it after WWII and sometimes gets pulled up by fishing nets. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [July 6, 2014, 5:39am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/6 "2014-07-06T05:39:06Z")
> [@engineer\_comp\_geek](#): > > when two WWII sea mines were found in the Ems River estuary (I have no idea where that is…). It’s the Dutch-German border on the North Sea. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [July 6, 2014, 8:54am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/7 "2014-07-06T08:54:47Z")
How to locate sea mines? Send in the dolphins! The military uses trained marine mammals – mostly dolphins and California sea lions – for exactly this kind of work. They are fabulously adept at it – dolphins can find a dime buried in the mud. This isn’t something out of _Day of the Dolphin._ The dolphins don’t disarm mines or retrieve them. They simply locate them and put some kind of a marker on them. They certainly don’t go kamikaze and detonate them, or place magnetic mines on ships like in the movie. As a military dolphin trainer once explained to me and some others: Dolphins are waaaaaaaaaaay too expensive to be treated as expendable, by the time you buy or capture one, get it trained, and all the care and feeding and facilities it takes. If you need expendable critters, you would be much better to use plain old human redshirts. [Military Dolphins and Sea Lions: What Do They Do and Who Uses Them? Military-trained marine mammals, including dolphins, can detect underwater mines and intruders.](http://news.nationalgeographic.com/news/2014/03/140328-navy-dolphin-sea-lion-combat-ocean-animal-science/) Jane J. Lee, National Geographic, March 28, 2014. > [@](#): > > Using marine mammals like dolphins, whales, or sea lions for military purposes isn’t new. Nor is it restricted to the Ukrainian or Russian navies—the U.S. Navy has had a similar program since the 1960s. The ability of these animals to detect and find targets at depth or in murky water is something technology can’t duplicate yet, but which militaries find very valuable. > > The Sevastopol-based “combat dolphins” are trained to search for and tag underwater mines or unwanted divers or swimmers attempting to access restricted waterways, says RIA Novosti. > > The U.S. Navy trains its marine mammals—including California sea lions and bottlenose dolphins—to find and retrieve equipment lost at sea and to identify intruders swimming into restricted areas. The dolphins are also used to detect underwater mines, either buried in the seafloor or floating from an anchor. ---
**Author:** ![Mogle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mogle/32/12021_2.png) [@Mogle](https://boards.straightdope.com/u/Mogle)\ **Post date:** [July 6, 2014, 10:02am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/8 "2014-07-06T10:02:19Z")
> [@engineer\_comp\_geek](#): > > They weren’t all successfully removed. A quick google search found that they’ve found some as recently as 2012, when two WWII sea mines were found in the Ems River estuary (I have no idea where that is…). Yes, for instance the Baltic Sea is full of them. According to the Swedish Coastguard, of the 165 000 mines that were deployed there during WW2 it’s estimated that around 40 000(:eek:) still remain. ---
**Author:** ![Donnerwetter](https://avatars.discourse-cdn.com/v4/letter/d/b2d939/32.png) [@Donnerwetter](https://boards.straightdope.com/u/Donnerwetter)\ **Post date:** [July 6, 2014, 10:44am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/9 "2014-07-06T10:44:55Z")
I’m looking at a table (in German) listing incidents with naval mines after WWII: [http://www.wlb-stuttgart.de/seekrieg/minen/minenverluste.htm](http://www.wlb-stuttgart.de/seekrieg/minen/minenverluste.htm) According to this, ships were damaged or destroyed for more than a decade after the end of WWII. The last recorded incident occurred in 1957 with 3 fatalities. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [July 6, 2014, 5:11pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/10 "2014-07-06T17:11:42Z")
Also keep in mind that shipping tends to go in certain ‘pathways’ so if the mines are not within a certain distance they may not be discovered until a fisherman or private boater finds them. Let me see if I can find a [shipping lane](http://en.wikipedia.org/wiki/Sea_lane) chart online - I have a couple in the barn but no scanner large enough to scan them in unless I fold them all to hell. Ha, perfect. [This is a chart](https://www.lib.utexas.edu/maps/historical/pacific_islands_1943_1945/shipping_routes_national_interest.jpg) showing the main shipping lanes used in the Pacific in WW2 - color coordinated by nationality. You can be very certain that the mines will be centered on the areas around the entrances of harbors, _generally_ laid in a pattern known to the people laying them so their shipping can thread through the pattern. Of course, intending that the enemy would try to go in and hit an area of the pattern. Minefields are a denial of access passive attack. The US and Australian forces removed our own minefields easily [of course, we had our own charts of their locations] but what had kept us busy was removing all the Japanese Imperial ones as frequently by the time we were rolling in to some small island base we were only clearing a path in to drop in troops, and after the combat the Japanese were dead or their charts were otherwise unavailable. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [July 7, 2014, 4:12am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/11 "2014-07-07T04:12:10Z")
Many sea mines have been found every year, but probably the detonation systems had failed by 1957… They had some idea of where mines were placed by the loss of ships to them, and by inspecting obvious places for mines to be placed. Here’s a discription of the work to do around Australia in 1945 > **[Mine Job For Navy - The Daily News (Perth, WA : 1882 - 1955) - 30 Oct 1945](https://trove.nla.gov.au/newspaper/article/78482780?searchTerm=navy%20mine%20clearing&searchLimits=)** > > MELBOURNE, Tues—To ensure that seas to the south-east of Australia and around the Barrier Reef are ... Many mines may be in water too deep,eg washed there or dumped there. Its remotely possible a mine will detach and float up and detonate when near/touching a ship somewhere someday. But the mechanisms probably failed in the time since 1957, many mines have been found at the shore or floating, with no ship losses. ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 7, 2014, 10:47pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/12 "2014-07-07T22:47:33Z")
> [@Isilder](#): > > Many sea mines have been found every year, but probably the detonation systems had failed by 1957… > [@Isilder](#): > > But the mechanisms probably failed in the time since 1957, many mines have been found at the shore or floating, with no ship losses. You _dare not_ assume this. It doesn’t matter _how safe_ it ‘looks’, do not assume this. I know of several pieces from WWII and WWI that had fusing systems still armed/dangerous when stumbled on. And floating mines that have beached themselves have simply not had the right trigger to detonate–either magnetic or hard metallic contact (it takes a whack). The damn things still contain explosives, and some knucklehead climbing onto one, using one of the horns as a handhold or footstep can _easily_ detonate it. Want to climb a mine? Find one sunk into the earth. Not one bobbin’ around in the water or washed up on a beach. Tripler Please kids, don’t try this at home. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [July 8, 2014, 4:35pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/13 "2014-07-08T16:35:06Z")
> [@Little\_Nemo](#): > > On the first page of images for WW2 sea mines, you get this picture: > > [http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg](http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg) > > You really have to give those guys back in World War II credit for being masters of camouflage. I wish you’d marked that NSFW. Hope my agency’s censors understand. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [July 8, 2014, 4:43pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/14 "2014-07-08T16:43:44Z")
> [@Little\_Nemo](#): > > On the first page of images for WW2 sea mines, you get this picture: > > [http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg](http://chivethebrigade.files.wordpress.com/2013/02/ww2-sea-mines-500-14.jpg) > > You really have to give those guys back in World War II credit for being masters of camouflage. Mine! Mine mine mine! ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [July 8, 2014, 6:04pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/15 "2014-07-08T18:04:40Z")
“I’ll disarm her, sir!” “No, me, me! I volunteer!” ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [July 8, 2014, 6:20pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/16 "2014-07-08T18:20:34Z")
> [@engineer\_comp\_geek](#): > > A lot of that stuff was dumped into the ocean to dispose of it after WWII and sometimes gets pulled up by fishing nets. Naval mines were disposed of at sea? :dubious: ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 8, 2014, 6:28pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/17 "2014-07-08T18:28:21Z")
> [@Tripler](#): > > Want to climb a mine? Find one sunk into the earth. Not one bobbin’ around in the water or washed up on a beach. No, not even then, as I remember a mate who had been in EOD rather forcibly telling the son of a friend. A mine that’s been buried can be exposed by wind, rain, and tide. And I’m sure you know the story of the Grand Slam Bomb that was mounted as a gate guardian at RAF Scampton and found to be live over a decade later. :eek::eek: All ordnance should be treated as live ordnance until known otherwise. > [@Elendil\_s\_Heir](#): > > “I’ll disarm her, sir!” Surely you want a dyslexic judge to disbra her? 😃 ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [July 8, 2014, 8:35pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/18 "2014-07-08T20:35:01Z")
> [@Quartz](#): > > …All ordnance should be treated as live ordnance until known otherwise. Quite right: [http://www.foxnews.com/story/2008/05/02/virginia-man-killed-in-civil-war-cannonball-blast/](http://www.foxnews.com/story/2008/05/02/virginia-man-killed-in-civil-war-cannonball-blast/) > [@Quartz](#): > > …Surely you want a dyslexic judge to disbra her? 😃 I’ve been told my sense of humor can be quite disarming. ---
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [July 8, 2014, 10:08pm UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/19 "2014-07-08T22:08:16Z")
> [@carnivorousplant](#): > > Naval mines were disposed of at sea? > :dubious: Not just mines, but artillery shells, small arms ammo, dispenser assemblies, bursters, mortar rounds, propellant of all sorts, you name it. Apocryphally, there are stories from the end of the War, where school buses were loaded with already produced munitions, which couldn’t be demilitarized without cost, nor shipped to a war that was no longer in progress. So, they just loaded up teh bus, drove it to a swampy spot in Southern New Jersey, and drove the bus in! There are not-so-dubious stories of similar munitions crates being simply dumped overboard for similar reasons. Yep, it happens. Farmers tend to plow them up on old artillery ranges. Subdivisions have the same problem, especially after wildfires\*. > [@Quartz](#): > > No, not even then, as I remember a mate who had been in EOD rather forcibly telling the son of a friend. A mine that’s been buried can be exposed by wind, rain, and tide. And I’m sure you know the story of the Grand Slam Bomb that was mounted as a gate guardian at RAF Scampton and found to be live over a decade later. :eek::eek: All ordnance should be treated as live ordnance until known otherwise. Oh yeah I know that story! I also know the story from Delaware about the mustard round too. _Everything_ is suspect until proven otherwise. Tripler - I responded to a couple of those subdivisions. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [July 9, 2014, 3:31am UTC](https://boards.straightdope.com/t/a-couple-of-questions-about-sea-mines/692456/20 "2014-07-09T03:31:49Z")
In Clive Cussler’s thriller _Vixen 03_, a military-surplus company sells what they believe to be live 16" armor-piercing battleship shells to a VFW post. The vets plink away at the shells from a distance for a Fourth of July celebration, hoping for a big bang, but nothing happens, so they assume the shells are duds, and display them outside their meeting hall. Turns out the shells had special fuses because they were carrying an extremely nasty biotoxin all along. Fortunately, they’re eventually tracked down, recovered by the government and safely disposed of.