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smart shrimp crab pots

cam, rf link for crap or shrimp pots (traps)
  (+3)
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Smart shrimp/crab pots show images of underwater trap. When deployed, operator may remotely check traps without having to physically haul them out of the water, to see what is in them.

Rugged, underwater camera and light source are integrated into standard crab and/or shrimp traps. Data cable integrated with buoy line to RF (radio) transmitter integrated with buoy (float which is attached to the trap). Special buoy uses solar cells and Baylis -type generator. Generator obtains energy from an internal weight, moved by wave action. Solar cells likewise trickle charge buoy battery from available sunlight.

wod_observer, Jul 28 2012

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       Neat. [+]   

       But the marine environment is notoriously harsh. The equipment's going to need some serious hardening, which is going to make it expensive.
8th of 7, Jul 28 2012
  

       [+] Sounds like a brilliant idea to me. I presume crab/shrimp/lobster fishermen waste a lot of time hauling up pots that ought to stay down longer?   

       I don't see why it needs to be expensive. Cheap webcam guts $10, add LED lighting $5, encapsulate the whole thing in PDMS, $2. Cable and transmitter would be the main costs, I would guess.   

       Instead of a solar cell and RF transmitter, why not terminate the cable in a connector? Boat pulls up, plugs in (both power and data) and there's the image.   

       Normal lobster creels seem to cost anywhere from $5 to $30.
MaxwellBuchanan, Jul 28 2012
  

       // I don't see why it needs to be expensive. Cheap webcam guts $10 webcam guts $10, add LED lighting $5, encapsulate the whole thing in PDMS, $2. Cable and transmitter would be the main costs, I would guess. //   

       Oh, the naiivety … guess again.   

       It's going to have to be pressure tight, with a suitable lens and protective cover. All external fittings (anchor points) need to be stainless steel. The casing needs to be thick enough to take rough handling; a rubberised jacket would help. Don't forget, something may try to eat it.   

       Works inside box- yes, $30 piece part cost. But the enclosure? $200 and up …
8th of 7, Jul 28 2012
  

       //guess again. //   

       Read again.   

       Just cast the whole thing into a gob of PDMS. You will never be able to open it again, but you don't need to. Total cost will be on the order of $2 (probably less if you buy your PDMS by the gallon). PDMS (which is glorified, optically transparent silicone sealant) is tough, waterproof and will work absolutely fine.   

       In terms of pressure - most lobster and crab fishing is done at depths that will not bother an encapsulated camera.
MaxwellBuchanan, Jul 28 2012
  

       Lobster fishing, yes. Some crab fishing is done in very deep water, maybe not deep enough to harm the camera, but possibly deep enough to interfere with transmission. The other factor these things will have to contend with is bitter, bitter cold.
Alterother, Jul 28 2012
  

       //deep enough to interfere with transmission// That's why I would suggest a simple wire; I don't know what the maximum cable length for a webcam is, but I'd guess it's quite long.   

       //bitter, bitter cold.// Webcams are fine at 0°C, and even -20°C (I have used one in the -20 room at work).   

       Incidentally, PDMS can be index-matched to water quite well. This means that the lens-side of the PDMS gob only needs to be case approximately flat, and the image will be fine. Even scratches or gouges on the PDMS will not really impair the image.
MaxwellBuchanan, Jul 28 2012
  

       It is not the cost of this idea compared to a normal lobster pot's which is relevant. The idea's cost must be weighed against the benefits gained by the fisherman in knowing whether or not to retrieve the pot.   

       I tend to agree with [8th] that hardening something to a degree suitable for seawater immersion and commercial use will be expensive, but this needs to be offset against the cost/value of the boat and crew per hour currently which is wasted pulling pots at the inappropriate times. [+]
AusCan531, Jul 29 2012
  

       I can't wait for this product. I really want to find out how "smart" shrimp taste, as opposed to the less-gifted type...but perhaps the answer is in the idea's subtitle.
jurist, Jul 29 2012
  

       //I tend to agree with [8th] that hardening something to a degree suitable for seawater immersion and commercial use will be expensive//   

       I truly don't see how or why. Conventional camera enclusures are expensive because they have to be openable, and typically protect an expensive camera. In contrast, placing a webcam-style camera in a mould, pouring in PDMS and leaving it to set is cheap and simple.   

       How do you imagine that a camera, encapsulated in this way, will fail?
MaxwellBuchanan, Jul 29 2012
  

       I used to build underwater electrical connectors and such gear for the offshore oil, oceanographic and military markets.   

       [8th] is correct, much care is taken in the fabrication and still the failure rate is high. One air bubble in the wrong place and it gets forced out during use, making your gear look like somebody shot it. Pressure changes from deployment and retrieval, tidal and wave forces, all continually pull at your best laid plans.
normzone, Jul 29 2012
  

       // making your gear look like somebody shot it //   

       Errr, no. That was us, actually. We thought it was french, so we shot it. Sorry. it seemed like a good idea at the time.   

       [Max], if you can make it work with PDMS then great. Yes, it's a superb material; we use it ourselves. But expecting it to stand up not just to the pressure but the battering and abrasion and corrosion of the sea is quite optimistic. We wish you every success.   

       Oh, and what [norm] said.
8th of 7, Jul 29 2012
  

       Though I have little expertise in marine equipment, several years of working in freight rail taught me that nothing is indestructible and that simple, rugged, well-designed devices often break in fascinatingly complicated fashion. Somebody saying things like "how could something like that go wrong?" often compel me to start compiling a list. Add use in the open ocean as a factor and that list suddenly becomes much longer.
Alterother, Jul 29 2012
  

       How strange ... we react to the statement "It's safe. there's no way it's going to go off" in exactly the same way ....
8th of 7, Jul 29 2012
  

       // battering and abrasion and corrosion of the sea//   

       Lobster isn't usually battered. More particularly, the camera will be inside a lobster creel (preferably in that part of it which is inaccessible to the lobster). As to corrosion, silicone is not noticeably vulnerable to corrosion.   

       Pressure changes and trapped air - well, maybe. The solution to that is to ensure that the webcam itself is not airtight then, after immersing it in the liquid PDMS, stick the whole lot under vacuum (which is how you debubble and degas PDMS anyway), wait til it stops bubbling, then let it set under normal atmospheric pressure. The PDMS will then have filled every interstice of the camera and, being non-conductive and optically clear, it'll all be fine.
MaxwellBuchanan, Jul 29 2012
  

       // it'll all be fine. //   

       Another statement that automatically puts me in mind of twisted metal and bad-order tags.
Alterother, Jul 29 2012
  

       In a TV documentary not so long ago, the Commander of the Britannia Royal Naval College, Dartmouth, was questioned as to why one of the significant parts of the training of a modern RN officer, given the preponderance of high-tech in the Navy, involved learning to sail a dinghy by hand and eye.   

       His answer was, "Because the sea doesn't change."   

       No matter how good your idea, the sea will always find the weak spot. t would be some sort of reassurance of it could be put down to malice; what makes it worse is because it's totally indifferent, and utterly relentless.
8th of 7, Jul 29 2012
  

       If you love something, don't put it into the sea.
AusCan531, Jul 29 2012
  

       Unless it's a dolphin, presumably.
8th of 7, Jul 29 2012
  

       So, if I take one of those super-bouncy balls, tie a piece of string to it, and then lower it to the seabed, it'll just spontaneously implode or something in the first month? Wow - tough gig. I wonder how they get $10 lobster pots to survive. Or indeed $10 lobsters.
MaxwellBuchanan, Jul 29 2012
  

       The $10 lobsters survive in the sea because that's what lobsters do. Even then, it's a hard life.   

       $10 lobster pots don't survive in the sea. That's why we sell them to tourists. A well-made modern lobster pot like those used by Maine lobstermen runs around $200.   

       And, no, the bouncy-ball on a string will not explode when you put it in the ocean; it will just disappear, like most of the other stuff mankind has put into the ocean throughout history.
Alterother, Jul 29 2012
  

       In that case, if I'm investing in a $200 lobster pot, I might not balk at spending and extra $50 for an encapsulated webcam. Methinks that $50 would do the trick.
MaxwellBuchanan, Jul 29 2012
  

       //I'm investing in a $200 lobster pot//   

       As I said earlier, the cost of the lobster pot is irrelevant. The point to be considered is the cost of boat time and labour saved with a $50 webcam or even a $200 webcam. I actually voted for this idea but am very leery of casually submersing something in the sea under working conditions and expecting it to keep functioning long-term with minimal maintenance.   

       I think [Alterother] expresses my sentiments very well. Having personally experienced enough of those "how could something like that go wrong?" moments has made even a natural optimist/ 'yes it can be done' guy like me wary.
AusCan531, Jul 29 2012
  

       As a diver, I can attest that those lobster pots are scattered all over the bottom in various states of damage and disrepair...
normzone, Jul 30 2012
  

       The beaches up this way are strewn with horribly expensive-looking stainless steel commercial fishing beacon buoys. These things look to be easily over $1k worth of solar, batteries, electronics and other paraphenalia. There's something like 10 units on the beach every kilometer.   

       I can't imagine they plan to lose this kind of gear, but they do anyway...   

       Look I think it's a good idea, it'll just be down to cost per unit vs acceptable losses. There are ways to harden underwater electronics, and there is also a random failure rate to accept. "Use sillicone" isn't really the answer, but could form part of it. Ultimately it might be cheaper to put a load cell on the winch or davitt arm on the boat to detemrine if the pot is heavier, therefore full, rather than having expensive, inherently fragile electronics attached to each pot. Remember you'll need lighting on the camera, function will be subject to visibility issues (not to be underestimated), as well as have marine growth to worry about.
Custardguts, Jul 30 2012
  

       I'm not exactly sure why there has to be an expensive camera system in these crab/shrimp pots. The fisherman is mostly interested in whether his trap is full and worth bringing to the surface.   

       To facilitate that, why not arrange a simple AA battery and LED connected to a fiber-optic strand attached to the trap's buoy line. If the trap is occupied with sufficient occupants, their weight will depress a simple contact switch plate which connects the inexpensive battery and LED and displays a small light on the other end of the fiber-optic strand atop the surface buoy.   

       Now we're talking about a dollar's worth of batteries which get replaced every time the trap is hauled on board. Simple.
jurist, Jul 30 2012
  

       Would it not be simpler still to make a one-way neck sleeve connecting the trap to the surface buoy? Crabs or lobsters could crawl up but not get back down because of flexible, curved, blunt spines pointing vertically up the neck sleeve.   

       They could then be collected from a much larger container much closer to the surface and the trap can remain submerged.   

       // In that case, if I'm investing in a $200 lobster pot, I might not balk at spending and extra $50 for an encapsulated webcam. //   

       You might wish to consider that, as a professional lobsterman or crab fisherman, you are not investing in a $200 lobster pot; you are investing in _dozens_ of $200 pots (I neglected to mention previously that this rough estimate includes necessary gear such as the tackle, moorline, and bouy).   

       On the coast of Maine, the smallest one-boat enterprises typically set 30-40 pots. Adding a lobstercam to each pot, assuming the $50 price tag, tacks on $2K. Since you already operate on a shoestring, that's probably two grand you only wish you had.   

       If you are a more successful lobsterman, you may be running four or five boats, each tending as many as fifty pots. The cost for lobstercams has now run into the tens of thousands of dollars. Are you balking yet?
Alterother, Jul 30 2012
  
      
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