where is the forward looking sonar at?

[thierry0509]

The forward looking sonder wast the best investment i made during my 5 years world sailing tour.
Range is easy to adjust and should increase with the speed that should not exceed 6 knots to be efficient.

[Sputnik]

I have B&G forward scan.......absolutely hopeless at any speed. Changed various components under warranty, no change. Installed as per the distractions......should have got a refund, but lived in hope that a software update might resolve the issue. I have spent many hours working on it and speaking with B&G. Had it now 2 years, no better.
If you consider the geometry, the more shallow the water is the less the angle from the transducer to the bottom, therefore the sound pulses ricochet off of the bottom and to not return to the transducer. So they are great until you get into a position of shallow water!
A 3d system would be better for us, as we "creak crawl" so are always looking for the channel, however, they are about 3x the price. I thought that I could weave my way down to "see" where the channel is, but alas no joy.
FWIW.
Neil

[svbravo]

We installed a ForwardScan on our old boat when we were a few years yo-yo'ing back and forth between NZ, Oz, and the islands. Lots of coral, lots of uncharted bommies to avoid. Though we, of course, always tried to enter an anchorage at mid day, sun at your back, clear water, etc.....it obviously isn't always possible. I liked the unit, when expectations are kept in check. It's NOT a replacement for good eyeball navigation w/ someone on the bow, but it can definitely augment it. And thats a good thing. Yes, you have to be going nearly dead slow, but you are anyway when entering a coral anchorage w/ unknown coral heads, right? No, you won't see containers on the ocean going 6 knots, but thats not its good for.

We liked it enough to add one to our new boat, launched a couple of weeks ago.

[MickMeck]

Originally Posted by robinmay

Hi everyone,

I've been doing a little bit of research on forward looking sonars / depth sounders. I was surprised to find few post debating the technology here on the forum and mostly 5 or 10 year old reviews elsewhere. Hence this post, to do a bit of probing (pun intended) as to your experience if you have one.

Has the technology gone through a fad but revealed to be disappointing?

Do you have one?

What sort of range do you think is useful, at what speed and how far from the coast?

And anything else you'd have to say

Fair winds!

I installed The B&G ForwardScan Sonar July 2018. I can honestly say that I have been very disappointed in it. Yes, the manual says it sees forward 8 X the depth - but that is the maximum. The nominal view is 4-5 X. So, in 6 feet that is 24 to 30 feet ahead of where it is mounted - normally midships. So, you really must be going extremely slow to have it make a difference.

Also, if you use the automatic depth and forward range the screen tends to jump all around frequently making it difficult to read. If you put a fixed depth and range then when it is out of the range for a while, it seems to shut it self off. I have frequently been coming into shallow waters for the thing just to shut down and I am left without it.

Another challenge is 'what is the depth you're looking at represent?' When looking forward, say 25 feet is the depth you are looking at directly in front of the bow? Or, as one technician said - it has a 15 degree arch so it covers much more than just a single line in front of the transducer. Ok, I asked, how is that displayed on the screen. No answer. So, there needs to be better instruction on how to read the screen.

Installation was a real challenge. They provide one cable hard wired. I have a 43 foot sailboat. The cable was not long enough to snake its way from the installation point to the Zeus3 chartplotter at the helm. Also, the connector was larger than most of the places I needed to get through. Eventually I had to cut the wire and use waterproof connecters to get it connected. I also had to add additional wires to make it to the helm station. Two things the manual says to try not to do. I didn't have a choice and I wonder if the poor performance is due to resistance of the connectors and additional line.

Power consumption when sailing is always a concern. When in shallow water this should be used. But when I have 20 feet of water beneath me I would like to turn it off (along with other things not being used). There is the ability to pause the system but that does not turn off the power consumption of the transducer. I find myself unplugging it. There should be a switch to turn it off.

Bottom line - while I do find that sometimes it gives me a false sense of security while transiting shallow areas, it would not be a purchase I would do again.

[Auspicious]

I've used about a dozen units on delivery. In my previous life I managed the development of a side-scan sonar that pushed the state of the art in SOG, resolution, and towbody stability. I now something about acoustic imagery. *grin*

There are two major issues with recreational forward looking "sonar." The effective range is really short and due to that you have to stare at it to have sufficient reaction time. The latter means a one person watch becomes a two person watch. That may (MAY) be okay in an anchorage but is not okay for an ICW snowbird or any other shallow water transits. If you try it do it all yourself you're going to miss something else.

My approach to uncertain anchorages when easing in and watching the depth sounder doesn't work is to anchor in the roadstead and sound the approach and anchorage from the dinghy.

[PeterBernard]

We have a B&G Forward Facing Sonar, and are pretty disappointed with it to be honest.

I bought it after reading an article in a sailing magazine which boldly stated that forward facing sonar was set to be the most significant development for cruising sailboats since the invention of roller furlers.

A big claim indeed.

We went into it with what I thought were realistic expectations. We knew it won’t help at cruising speeds (to avoid shipping containers, reefs or debris), instead we expected it to be particularly useful when going at low speeds in unfamiliar anchorages.

What we’ve found is that it provides many, many false positives - the display jumps around extremely erratically, to the extent that it becomes an unwelcome distraction at a time when you are on high alert and often consulting charts, google earth imagery, Mk1 eyeballs, traditional depth sounder etc etc.

It is also unreliable in terms of its unreliability! Sometimes it behaves calmly, and you can see a gradient ahead, other times the false positives and erratic behaviour renders it totally useless. And those two scenarios can happen on consecutive days in the same anchorage, and sometime even in consecutive minutes.

I should add that its behaviour is best when you are travelling at least than 2 knots in less than 10 m of water (so typical anchorage conditions), but the flaws I highlight above still manifest themselves.

In case you were wondering, this was a professional installation at a time when we replaced all of our instruments and plotters with B&G, so not a compatibility or installation issue so far as I can tell.

We do still turn it on in new anchorages, but I have learned to view its results with extreme caution, and have turned it off at times when it was becoming a distraction.

I wouldn’t buy it again if I had my time over.

[David Mathis]

Since they’re only functional at slow speeds and have a protrusion sticking down which is sure to be broken by a floating stick, I’ll wait for the new and improved model. The cruise speed on our 43’ cruiser is 23-25 knots and with both engines at idle, the speed is about 5.5 knots, the ones presently available would be more flash than function. I’ll wait a few years then look again.

[Looking4Neptune]

How useful would FS be on my catamaran with a 25 ft beam? I mostly want to use it the way Ann described, slowly looking around an anchorage. Do I need one transducer on each hull? Otherwise, how do I see a coral head that is in front of the hull that does not have the transducer? How wide a fan is scanned in front of the transducer?

The high end Echo Pilot has two transducers, gives a 3D view and claims to have a 20 to 1 look ahead. That would be really impressive but I saw a review from Practical Boat Owner (from 2016 - maybe it is better now?) that did not seem to support this. iMarineUSA has it priced at $11.9k but not currently in stock.

Thats out of my price range (by a lot!) and I am hoping that something like this will be available in the next few years for under $2k. Yes, I can dream...

[conchaway]

I have recently discovered a fantastic device for determining underwater depth ahead of a boat. It is called the Retractable Overwater Device-- Take a fishing rod, and tie a sinker on the end. Eight feet up from the sinker, attach a bobber. as you go slowly along, have someone on the bow cast way out ahead of the boat. If the bobber goes under, keep going. If the bobber floats on top, try elsewhere.
This is a fantastic new method called "Casting the Leadline".

[Zeilzwerver]

I have used the Interphase Probe for some 10 years until the display faded beyond the point to where it was not useable anymore and replaced it with the B&G Vulcan/Simrad forward looking sonar.
Forward range is limited, as others remark, but I find it very useful to see a trend in the bottom getting shallower or deeper. And it is very useful in approaching coral reef walls.
My new B&G however is very instable. It does not show depths reliably, depth display drops out. Depths figures and bottom display go wild sometimes when going steady over a flat bottom. It happens regularly that you have no idea what is happening!
It took experience to work the Interphase but the B&G is hopelessly unreliable so far.
Anybody have experience with the B&G?

[Dockhead]

I have the Echopilot Gold; was part of the original build of the boat.


It is only useful in an extremely narrow range of conditions. As others have said -- basically feeling your way around at 1 or 2 knots, in an unknown anchorage.



Not really useful above 2 or 3 knots.


Mine is mostly used as a reserve depth sounder.


Not sure it's worth the money.

[Cpt Mark]

Originally Posted by Zeilzwerver

I have used the Interphase Probe for some 10 years until the display faded beyond the point to where it was not useable anymore and replaced it with the B&G Vulcan/Simrad forward looking sonar.
Forward range is limited, as others remark, but I find it very useful to see a trend in the bottom getting shallower or deeper. And it is very useful in approaching coral reef walls.
My new B&G however is very instable. It does not show depths reliably, depth display drops out. Depths figures and bottom display go wild sometimes when going steady over a flat bottom. It happens regularly that you have no idea what is happening!
It took experience to work the Interphase but the B&G is hopelessly unreliable so far.
Anybody have experience with the B&G?

I bought my B&G fwd sonar about 2.5 years ago. Because I have mainly been working on the boat I have little experience with it. The other day I was seeing shallow water and called back to my buddy with the deep draft. His depth sounder read 50' while my B&G read 8. This happened quite a bit and we started comparing depths at locations. B&G was off a lot of the time and correct some of the time.

[merrimac]

I'm getting used more and more to having the Navico (B&G) forward scan open when we approach an anchorage and now that we've moved from the 1-2m meter depths in the Netherlands to the Caribbean it's actually quite useful.


If you say it is incorrect, does the depth that it gives as the actual depth match up with the sonar image? Did you put in the correct deadrise in the installation settings?

[Zeilzwerver]

Thanks for your input!
The fact remains that my old Interphase Probe was working quite acceptable and the much newer product from B&G is not working reliably at all.
I will pursue the matter further with B&G!
Regards
Hans van Rijn

[Zeilzwerver]

Originally Posted by merrimac

I'm getting used more and more to having the Navico (B&G) forward scan open when we approach an anchorage and now that we've moved from the 1-2m meter depths in the Netherlands to the Caribbean it's actually quite useful.


If you say it is incorrect, does the depth that it gives as the actual depth match up with the sonar image? Did you put in the correct deadrise in the installation settings?

Deadrise is set correctly and it does function correctly at times. But when sailing in stable conditions over a flat bottom it will suddenly become instable and depth figure and bottom profile start jumping around. The R side of the display will fill up with data points and the envelope will match the data points so it looks as if you are heading for a wall. On occasion I found I could 'reset' it by going 'Stand by' for a minute. I found Noise Suppression set for level 3 works the best but it will still become unstable without any apparent reason.
The way the B&G/Simrad works is totally unreliable!
I am in contact with Simrad support but so far they have not come up with a solution.
The transducer is mounted where Simrad advises on a steel displacement monohull....Very frustrating!