Simrad ForwardScan, a challenge to EchoPilot FLS?

Simrad_ForwardScan_concept_aPanbo.jpgWhile Simrad announced ForwardScan at the Miami Boat Show, details are scarce and the concept diagram doesn’t really show what a ForwardScan screen is going to look like. Yes, like other Forward Looking Sonar (FLS) systems, the goal is to display the water column and ocean floor in front of the vessel to “help boaters eliminate the worry of potential groundings in unfamiliar waters,” and yes, FowardScan is the first FLS to be fully integrated into a multifunction display system. Well, I’ve hounded Simrad for more information — all of which sounds good — and it also looks like I will get to test ForwardScan against what seems like the most similar existing product…


Simrad_NSS_evo2_rear_view_ports_cPanbo.jpg



First there’s the news that the $699 ForwardScan option will not require a black box. There will simply be a software update to the Simrad NSS evo2 combo displays that already include CHIRP Sonar and StructureScan HD, after which an installer can just plug the ForwardScan transducer into that #7 port shown above. Obviously one NSS evo2 can not be connected to both Structure- and ForwardScan transducers, but if you have two MFDs on the network, both will be able to show both types of sonar (as well as regular fishfinding). The SonarHub module will get a similar update, so it will be another way to get ForwardScan (plus more varieties of CHIRP) onto a Simrad network, including existing NSS Sport, NSE, and NSO displays {correction: SonarHub works with older Simrad MFDs but ForwardScan will only work on evo2 models}. (I presume that B&G Zeus2 displays will also get ForwardScan capability eventually, as FLS is a type of sonar that keelboaters tend to care about 🙂

Simrad_ForwardScan_transducer_aPanbo.jpg

Simrad has published a photo of the ForwardScan transducer, which fits in a standard Airmar retractable housing. In fact, I understand that they may soon offer a housing kit so that anxious boaters will be prepared when the transducer ships, possibly “midsummer”. I believe it will consist of a stainless SS617 housing and some fairing material, so the transducer can be installed vertical to the waterline. I’m going to use a similar bronze B617 in the same forward keel 2-inch hole where an Airmar DST800 smart transducer has worked pretty well, but that plastic housing is not recommended due to the leverage possible with a transducer that protrudes from the bottom about two inches. (Given the standard housing and built-in water valve, I could conceivably switch back to the DST800 or even the Airmar CA500 underwater camera I’ve long wanted to try, though I’m optimistic that ForwardScan will be worth a long test.)

EchoPilot_Bronze_2002_cPanbo.JPG



At any rate, note the similarity between the Simrad FLS transducer and the slightly larger EchoPilot transducer I installed about 12 years ago on good old Ralph. Indeed, ForwardScan will also project a narrow vertical sonar beam (about 10 x 85 degrees) that will extend from straight down — hence the depth reading directly below the transducer — forward and up almost to the water surface. And I’m told that ForwardScan will also use a bottom profile display something like what EchoPilot has evolved over the years, though purportedly “better”.

Now that particular small, monochrome EchoPilot Bronze display above is the bottom of their line, and I’m not sure I ever saw it at its best (there may have been a connector issue), but even when I didn’t completely trust the Bronze to show me underwater obstructions ahead, my eye still wanted to check it out while poking around in unfamiliar and/or skinny waters. Not many boaters have tried even low end FLS, but that’s a natural display to use and potentially quite valuable.

EchoPilot_Platinum_FLS_Engine_aPanbo.jpg

Meanwhile, EchoPilot may be a small UK-based company (renowned for their satirical Christmas cards) but they’ve stayed focused on developing FLS. Their products are also now enthusiastically distributed in the U.S. by Gemeco, who approached me last fall about testing the Platinum FLS Video Engine seen above (putting FLS on a Garmin MFD). Gemeco said that many of their dealers, particularly along the rocky West Coast, report happy EchoPilot customers, and they wanted to get the word out. That was before Simrad ForwardScan was announced at less than half the price and it seemed possible for me to test both FLS systems head-to-head, but EchoPilot is confident that it will do well in comparison. The challenge is on!



EchoPilot_FLS_screens_aPanbo.jpg

Before this comparison can happen, I have much installation work to do and ForwardScan has to make it out of the development lab. The possibilities for safer, more relaxed cruising and exploring are exciting — and my PassageMaker friend Peter Swanson seems to share the feeling — but I will attempt to be reasonable about expectations because I know that looking ahead with sonar is hard. Back in 2002, I interviewed several FLS users for a still-online PMY article that’s aptly subtitled “Magic it’s not, but cruisers who understand forward-looking sonar’s limits are pleased with what it can do for them.” The EchoPilot demo screens above tell some of the story. A narrow forward fan beam cannot capture the bottom detail that can be created when a similar beam is fired sideways and added to the display line by line. EchoPilot also warns that its FLS cannot see ahead more than 8 times the current depth, and only promises a range of 200 meters in deep water (and I rarely see screenshots greater than 100m).

I understand that Simrad ForwardScan will have the same range and depth limitations, but maybe their engineers can tweak a clearer bottom profile out of a similar sonar beam, or maybe there’s something quite different about their beam. There’s a lot of nuance to this technology that we may never know, but we will eventually see the results. And let’s not forget that Garmin’s active sonar team has access to the assets of FLS developer Interphase, or that Furuno also seems to have relevant intellectual property and once previewed the intriguing FL-7000. Raymarine is no sonar slouch either, and the impressive seeming CPT-120 CHIRP sonar and downview transducer is also going in poor Gizmo’s bottom.

Finally, it’s fun to see what’s possible with a large budget for complex FLS transducers and processors. Gemeco reports that the $10,000 EchoPilot FLS 3D is also doing well (in a much smaller market) and the FarSounder demo videos are ever more impressive, with a claimed 3D 1/2 mile range even at 25 knots (though at about 10x the cost). It’s also possible to put a high-end multibeam sonar into a superyacht tender and send the data back to the mother ship over WiFi, which is what’s happening with a new WASSP feature illustrated below. (Come to think of it, most any tender could be equipped with the recently discussed SonarPhone T-Box.) Do you see some form of forward looking sonar in your boating future?



WASSP Wireless.jpg

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

25 Responses

  1. PaRaDoX says:

    I can’t see the point really with these “forward looking sonars”.
    You mention a price figure of 10,000 USD, for this amount you can fetch either a Furuno or Wesmar entry-level sonar like the CH-250/300. Wesmar has got similar offerings and also Suzuki has perfectly good competing product for less than 10k.
    A true omnibeam 2D sonar will give you much more bang for the buck. People wrongfully think of the 2D sonarheads as crippled, but the tilting feature is a powerful thing and since acoustic wave propagation is rather inexact to begin with and the beam diameter of most transducerheads is rather wide an experienced operator can easily interpret the 2D omnibeam into a 3D view of seafloor ahead.
    FLS systems are wrongfully called “sonars”, they should instead be labelled “Forward Looking Sounders” much like the Wassp being not a sonar but a multibeam sounder. But I guess in the end anything emitting sound underwater and calculating range from it is a sonar in the basic sence of the word but as it is daily used by people in the business, a sonar is a sonar and sounder is a sounder. But the line is definitely blurring with all these new products coming to market.
    As an inshore navigation and anti-grounding tool you’ll be far better of spending those 10k on a CH-250. You’ll get a professional quality product that is built for pro’s and not a gimmicky thingy that’ll break down on you when the air is a bit most or a wave slams into your bow etc.
    As for the Wassp/TimeZero combo that’s a feature that Furuno (which has bought a majority sharehold in ENL who developed the original Wassp-sounder) has failed to deliver despite promises being made many years ago. The software developers at Informatique & Mer seems unable to get the work done and the release is always “one year away” whenever you ask.
    We have had the original 160 kHz Wassp sounder for two years and it’s a great product. A TimeZero license was bought together with it with the promise of the Wassp compatible software update being “just months away”, now it’s been over two years and the USB-dongle holding the license just sits in a drawer onboard. The system is not even installed it’s so useless compared to the Olex implementation of 3D bathymetrics. Problem is the Olex is so far ahead it’s competition in it’s implementation that Sodena and MaxSea will never catch on. Olex is space-age technology compared to it’s so-called competition.
    If you really want to go far-out you could buy the Simrad MS70/ME70 (from the “real” Simrad in Norway), it’ll set you back about 800,000 US but it’s quite an amazing product.

  2. Ben Ellison Ben Ellison says:

    WASSP looks great, Dox, Olex too, but I think you missed the fact that Simrad ForwardScan will cost just $699 if a boater already has a fairly recent Simrad system. The EchoPilot FLS Platinum Video Engine is $1.399 plus transducer. In other words, the main discussion here is a whole other level of Forward Looking Sonar, or sounder.
    Also I think it’s safe to say that there are two real Simrads. There’s Simrad-Yachting.com, which has a huge global presence, and also plain Simrad.com, which is a major player in high end commercial fisheries. I’ve been to Horten, Norway, and seen the amazing huge transducers built there.

  3. Fred Muhl says:

    Transducer placement is hypercritical with forward looking sounders. Any recommendations?

  4. For what it is worth on my Halberg Rassy motor sailor I have used an Echo Pilot forward looking echo sounder for more than a decade in N. European waters.
    1. When the transducer is mounted appropriately on a keel boat two thirds of the useful beam is required to get the beam forward of the bow in shallow water. Hence by the time a rock is identified one is apron it.
    2. It is great when the water is sufficiently deep that it isn’t needed.
    3. I find that a regular sounder display works far better because it is easy to see the water shoaling ahead. Also, I find it difficult to simultaneously look at the FLS and the sounder. Using just the sounder is the way to go.

  5. Ben Ellison Ben Ellison says:

    Thanks, Adrian. That’s why I like to install FLS transducers well forward. EchoPilot cautions against this because of the chance that the transducer will come out of the water or get messed up by a bubbly bow wave, but I’m willing to trade high speed and/or rough water performance for better performance at modest speeds in calmer water (which is when I think the technology is more useful anyway).
    Besides, my boat has limited install options and one of the best is right on the keel about 18″ underwater and 6′ aft of the bow waterline. I installed three transducers there in 2010, including Interphase FLS, and all worked pretty well with the exception of the speed paddlewheel, which was expected as you can see here:
    https://panbo.com/archives/2010/04/gizmo_holed_for_a_sonar_summer.html
    I agree that a fishfinder-type sonar screen can help identify shoaling ahead because it shows the depth trend your boat has just experienced. But that doesn’t always work, especially in areas like mine where large ledges can loom quite steeply out of otherwise flat bottom. I want to see ahead, not just the trend.
    Fred, I think it’s important for an FLS transducer to be vertical to a boat’s true waterline, aimed dead ahead, and without obstructions in its beam. But the beam from the ForwardScan and EchoPilot transducers is narrow.

  6. Jerry says:

    Funny, anyone I knew that tried forward looking sonar (interphase) never could quite get the hang of it.
    I figured someone just might create a more user friendly approach to what it the picture actually means, but it sure looks just as awkward as when Interphase had it.
    Maybe GARMIN will make it getter.

  7. Ben Ellison Ben Ellison says:

    Hi, Jerry. I’m going to guess that what your friends had trouble with was Interphase’s horizontal beam mode, which definitely wasn’t obvious:
    https://panbo.com/assets_c/2009/10/Interphase_Ultrascan-1196.html
    I doubt that many people will have trouble understanding the profile screen derived from a vertical FLS beam. It’s quite like a standard fishfinder screen except that instead of just seeing the bottom profile below and behind you, you get at least some hints about what’s ahead.
    This EchoPilot video is not in English but does show screen action at the end:
    http://youtu.be/NsdA_Tl7wg4

  8. PaRaDoX says:

    First off, didn’t quite catch it that the EchoPilot FLS was only 1,399 the first time around reading. English is not my natural language (obviously) and upon reading the text again I now see that the 10,000 USD option you refering to in the text is some higher end variant of the EchoPilot FLS.
    However my point is still valid for those with a superyacht that in fact IS considering THAT 10,000 dollar option. They’d be far better off with a CH-250.
    And as for the Simrad-Navico offering for 699, that is just the beamformer/transciever unit, for a complete package you still need the MFD which can be quite costly. Of course like you said for someone already owning a complete Simrad-Navico system point taken but for a true comparison to competing offerings all costs should be taken into account. I take it that the 1,399 and 10,000 dollar offerings from EchoPilot are complete standalone systems.
    My point is that many people with leisure boats believe that the pro-stuff is so enormously expensive that it is out of reach compared to “yachting” products, but that is not always true.
    For example if you were to buy the NavNet VX2 or 3D MFD with radar option and choose the biggest antenna, that solution will actually cost MORE than an IMO type approved FAR-2117-BB commercial X-band radar with large open array scanner (and that is WITH the Hatteland 19-inch marine display!).
    The competing JRC and Koden offerings are even cheaper, and still very very good.
    Same goes with Olex, the entry level “Lino” version installed and ready to go on Olex’s own dedicated solid state 9-30 VDC computer which is extremely reliable and sturdy is something like 4,000 USD and that is with lifetime software updates and support.
    Of course it is not an option for small leisure boats typically equipped with Lowrance and Garmin low end plotters BUT for the superyachts and semi-pro sports fishers I can’t understand why they blindly choose these super-expensive top-of-the-line MFDs without not even considering commercial/pro-grade software and solutions?
    As for the matter of FLS’s, you don’t seem to take into account acoustic wave propagation and beam width / lobe diameter. As the sound leave the transducer it gets dispersed very very quickly. The smaller the transducer the bigger the problem, it is basically the same as radar theory but the problem underwater is much more prominent. Like you all know, the wider the radar array is, the more sharp the lobe is and hence the radar can better differentiate from objects close to each other that is far away from the array.
    Same goes for transducer arrays in sonars/sounders. User Adrian posting above touched a little bit upon this issue.
    To take an illustrating example from the real world:
    Those “amazingly huge transducers” being built at Simrad-Kongsberg in Horten that you were refering to earlier, well since I own a few of those I’ll use them as an example.
    When using the SP93/SX93 which consists of an array of 512 transducer elements (256 transmitting and 256 recieving) mounted/molded in a housing that is almost half a meter in diameter and half a meter in height (making it the underwater equivivalent of a really really big radar scanner).
    The SP90/SX90 has a Vertical Slice Mode which is basically the same thing as these FLS’s we’re discussing. If you run the sonar in the Vertical mode in 80-100 meters depth, the beams will “touch” eachother just a few hundred meters in front of the Vessel, making the bottom and surface echo indistingushable from one another. And for example if you have a school of 200-300 tons of herring extending from the surface down to maybe 20-30 meters say 100-150 meters away from the Vessel (still being 80-100 meters deep) the bottom of the fish will be next to indistingushable from the bottom. In reality there is still a good 60-70 meters left to the bottom where the school ends, but the sonar can’t tell the difference because the beam width is not narrow enough.
    Now this is a 300,000 USD piece of equipment we’re talking about here and 100 meters of water column. How on earth do you think that your 1,000 dollar FLS transducer element/array that is a few inches in size can possibly distingush surface and bottom 150-200 meters away at 10-15 meters depth!? It ain’t gonna happen and you’d be far better of spending your money on a really good sonar or sounder.
    When we do highspeed inshore navigation with our sonars you could never use the Vertical Slice, it just won’t cut it, the only way is to run high ping speeds on small range in omnibeam 2D and try to interpret the image much the same you do with radar taking into account all the equipments limitations.
    Many people also forget sidelobes. You can use sidelobes to see what’s ahead. On a very cheap and small echosounders not only is the beam diameter very wide but there are also “acoustic leakage” in the form of sidelobes that represents things to the side and to the front of the transducer. If you buy a marlin/tuna type Airmar sounder that has 30 to 40 degrees beamwidth and mount it slightly tilted forward you’ll actually see quite far ahead. And also when running over clay/mud rocks and coral will clearly be seen as sidelobes below the bottom line long before you’re over them.
    And that’s for a fraction of the cost of your FLS and you also got a super quality echosounder/fishfinder for free!

  9. John Hinckley says:

    It will only work with Evo2 units (“ForwardScan will only work on evo2 models”)?
    Will not work with pre Evo2(NSS, NSE, etc?
    I’m sure it’s not a technical limitation, but more a marketing ploy to get people to buy Evo2. I just bought an NSS12/4G system, which I am looking “forward” to, and I can’t say that I would want a FrowardScan, but when companies do things like this, it leaves a sour taste in my mouth…
    I would bet a conversation with the right engineer at Navico would reveal that it was perfectly possibly for Non EVO2 systems to talk with the FS…
    Hopefully I will be proven wrong, but the way it looks now it has a slightly bad smell…
    Apologies for the rant,I may be slightly jaded after 30 years in many different sectors of the high tech world…
    Thanks all,
    John

  10. Ren says:

    Any chance these things can pick up a container that is barely floating ?

  11. Hi all,
    Some interesting comments above,some from some very well informed people.
    1 However “Fred” above has just given a clue to his problem of short range.He mentions watching a vertical depth sounder at the same time.Using more than one sonar/sounder/fish finder is likely to cause acoustic interference,maybe turning down an AGC (automatic gain)circuit or giving a nonsense echo.
    Interference is more of a problem with sonar that are listening to a large area,and often happens despite different frequencies as there are usually harmonics which are multiples of each other.
    2 Oh yes,the upset gentleman who has already got an older Navico can of course always buy an EchoPilot!
    3 Containers.Hard to answer,in calm water when the surface is warm a sonar beam bends downwards so a container could be missed.In rough water a sonar beam will not pass through the air water interface,between troughs and crests.So the answer is sometimes but not to be relied on.
    However the Volvo (round the world race)safety commitee reported 17 Whale incidents for each man made flotsam incident.And yes whales give a tremendous echo!

  12. John Hinckley says:

    Thanks for the thought Mike. I could always buy an EP, but really, I was just grousing a bit.
    I don’t hold onto stuff like that for long.
    Not worth the energy!

  13. Gareth Hodson says:

    Dear PaRaDoX,
    With regard to your comments:
    As for the Wassp/TimeZero combo that’s a feature that Furuno (which has bought a majority sharehold in ENL who developed the original Wassp-sounder).
    I would like to correct you on this point, ENL is a privately owned company 100% by my family.
    Yes it took time to get the TimeZero interface pulled together, but pleased to say its now available and being used with WASSP succesfully today.
    We launched our second generation WASSP’s in 2013, we now have three products WMB3250 (160 kHz 224 beams), WMB3230 (160 kHz 112 beams) and WMB5230 (80 kHz 112 beams) with depth from 1=700 Meters. Target markets being Commercial Fishing, Survey Mapping (IHO), Work Boat, Defense, Search & Rescue and high end leisure. We currently interface with a range of software companies including MaxSea,Nobeltec Olex, Hypack, EIVA & QPS under license..with more to come. Along with our very own 3D/2D viewing software Navigator.
    Thank you for your understanding.
    Regards
    Gareth Hodson
    Managing Director-ENL
    http://www.wassp.com

  14. Ben Ellison Ben Ellison says:

    Thank you Mike and Gareth for posting comments here. It’s wonderful to have manufacturers participate in these conversations, especially considering that others are allowed to be anonymous and sometimes even obstreperous.

  15. PaRaDoX says:

    Hi,
    This is great news (if true), thanks for clarifying.
    The talks “on the docks” here in Scandinavia
    is that ENL was bought by Furuno and that when
    I&M is ready with the TimeZero interface they would
    pull the plug on Olex support (it is said this was decided by the Furuno board in Japan).
    Is all of this complete bollocks?
    Can you confirm that Olex support will not be dropped in the near future?
    We were on the verge of getting rid of our Wassp sounder and plan on switching to a Kongsberg EM2040 instead due to Olex support being planned to end…
    If any of this has no basis in reality whatsoever you really need be sending clarification regarding this…
    Here up north everybody believes this atm, ppl are afraid of buying the Wassp because Olex support is due to be dropped!?!?!?

  16. Roger in Croatia says:

    The big test, that no system seems to pass yet, is the waterlogged shipping container or the large balk of timber. Even the Mk1 eyeball lookout can miss these.
    The technical problem is surface wave ‘clutter’ on screen.

  17. Ben Ellison Ben Ellison says:

    I saw a Simrad/B&G ForwardScan recording today (at IBEX) that looked darn impressive. The transducer is already installed on Gizmo and a Navico tech will be coming aboard on Monday to update the NSS evo2 gear with beta software and show me how FS works around Baltimore. We may have a real breakthrough product here.

  18. Terry Williams says:

    Having purchased a complete B&G system ie Zeus 12MFD 4G Radar and depth,wind speed units last year I was dismayed to learn that the new FLS would only work with Evo2 MFD units.
    I like John think that this is a cynical ploy to get customers to purchase the evo2 units.When I purchased my units I asked the sales tech if B&G intended developing FLS.I was told yes, and not to worry it would be compatible with my units!!!!!

  19. Alex says:

    I’m reading in Simrad’s user guide on page 1:
    ForwardScan can be shared with NSO evo2, NSS evo2 and Zeus²
    ( http://www.simrad-yachting.com/Root/User%20Guides/Forwardscan_UG_EN_988-10761-002_w.pdf )

  20. Jorgen says:

    I have just ordered the forward scan unit. I wanted a ZEUS2 MFD go be driving it but my dealer (who has checked with the national Navico office) says that this is only possible if I also invest in a black box (the Sonarhob I guess) that will add considerably to the package cost.
    So one has no other choice than to buy the NSS evo2 MFD’s if you are on a budget!
    This contradicts the info above and is a strong indication that the Simrad and B&G series are no longer a copy/paste thing.
    Ben, can you see if my dealer (and his Navico backup) are correct on this. My experiences with the dealers tecnical insigth are very good.

  21. Ben Ellison Ben Ellison says:

    That’s correct, Jorgen. The B&G Zeus2 can display ForwardScan but the processing is done in a SonarHub:
    http://www.bandg.com/en-US/Products/ForwardScan/
    The Zeus2 is a lot like the NSS evo2 but apparently they did blank the two sonar ports. I wrote this entry before that was clear, but I’m not sure which info is contradicted?

  22. Itzmann says:

    We upgraded from a Zeus Touch 7 to a Zeus2 7 and I was quite surprised and disappointed to discover that the Zeus2 7 (MSRP $1199) blanked out the sonar port(s) that exist on Zeus Touch 7 and on NSS7 evo2 “combo” (MSRP $1199).
    This puts into question that entire presentation Navico made to you that B&G was no longer going to charge a surtax for the B&G logo moving forward.
    And so the Zeus2 7 $1199 is equivalent to the NSS7 evo “plain” whose MSRP is $1099, and also forces B&G ForwardScan customers to shell out an extra $600 for the SonarHub over what a Simrad guy would pay, for a total difference of $700.
    Not very nice.

  23. Jorgen says:

    Ben,
    I’m sorry. Using the word ‘contradict’ in my post was too strong wording. I didn’t read your fair presentation of the facts as they were by then well enough.
    Concerning the evolving clift between Simrad and B&G products I begin to think that this is the way to go for Navico. The very close similarity between Simrad and B&G that have have been there for a few years should be seen as something that only lasted while Navico was getting it’s hourse in order cost-wise after the mergers. As consumers we will in the long run bebefit from diversity in functionality and low costs in development.
    We should, however, also begin to think forward to part-shouldering the cost of bringing Navico public. The main ovner, Altor, has left a track record in the marine sector in that respect that some would say is not totally spotless.

  24. Ben Ellison Ben Ellison says:

    Thanks, Jorgen.
    I think I found a reference to the Altor track record you mention…
    http://www.bloomberg.com/news/articles/2014-11-06/ipo-that-raised-1-billion-implodes-in-denmark-after-8-months
    …but note that neither Altor nor the big Scandinavian and U.S. banks also involved in the IPO have actually been charged with complicity in the OW Bunker A/S scandal.
    At any rate, I think that Navico has been charging a slight premium for the B&G sailing features added to the same physical MFD Simrad sells. But then what they did with the evo2/Zeus2 was subtract some hardware features and make the retail prices the same.
    I certainly understand the frustration about having to get a SonarHub to run ForwardScan but it’s not entirely inconsistent with the longterm pricing strategy.
    Also, what Navico promised about B&G is that the line would eventually extend down market to all sailors…
    https://panbo.com/archives/2013/03/bg_in_las_palmas_products_for_all_sailors_.html
    …and I think that’s been true. Also, look for more evidence of that coming soon 😉

  25. abbor says:

    7 and 9″ NSS Evo2 comes in two versions, one with CHIRP and StructureScan sounders and one version, the m model (NSS9m Evo2), without sounder.
    B&G Zeus2 is based on the m model with added sailing functionality, the price for the B&G version is similar to the Simrad version with built-in sounders. I find this pricing reasonable.

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