forward looking depth sounders again

[Ric]

Usage

We had an Interphase Twinscope in boats from 1989-2010 and were very happy with it cruising in tropical waters and in the Pacific NW. When the last one failed, the company was out of action, so we bought an Echopilot 2D. Lacks the side scan mode and it doesn't look directly ahead (beam starts 30-45 degrees from water surface and sweeps to vertical) and the resolution isn't as high, but high enough to see your anchor as it is lowered. And it was around $1500, which was much more cost effective for something used intermittently. In general we use the system only for anchoring or when entering an area not clearly sounded on the charts. Great for finding shelf edges and slope gradients that help you figure out swing room during wind changes and falling tide. If you ever need the side-sweep view in a narrow channel, you can slow to a near-stop and swing the bow back and forth with the bow thruster.

 

[Alex F]

A term that I've heard here, in connection with some boating accidents, is when somebody's "driving the plotter" (instead of looking ahead, out the window).

New term for me too, but when bashing the "driving the plotter" operators, I think you have completely forgot that some people put tons of hours doing just that in poor or no visibility at all. Think of getting caught in thick fog, heavy rain and/or simply dark nights with no light pollution. Those are the times when you use the plotter(s) to "know" where you're going and the radar to "see" where you're going.

The "best combination" is dark night (no lighting from nearby land...think of rural areas of ICW) and heavy rain.

 

[ScottC]

New term for me too, but when bashing the "driving the plotter" operators, I think you have completely forgot that some people put tons of hours doing just that in poor or no visibility at all. Think of getting caught in thick fog, heavy rain and simply dark nights with no light pollution. Those are the times when you use the plotter(s) to "know" where you're going and the radar to "see" where you're going.

My point was that these people, involved in accidents, were "driving the plotter" to the exclusion of looking out the window (i.e. in fair weather). Sorry I didn't make that clear.

 

[Alex F]

My point was that these people, involved in accidents, were "driving the plotter" to the exclusion of looking out the window (i.e. in fair weather). Sorry I didn't make that clear.

Granted that on a clear day, a Nav equipment becomes an aid. But, it's important to have the reliable equipment and the knowledge to use it as primary navigation when looking out of the window doesn't present good picture for safe navigation.

Didn't mean to go off topic.....I'd love to hear and learn more about forward looking sounders. With exposed running gear I could use one.

 

[High Wire]

Would you trust it to keep you from running aground?

 

[Alex F]

Would you trust it to keep you from running aground?

All these years I've trusted my regular "down looking" sounder, which saved me countless times. Once we get to the point (and maybe we already there) where FWD looking sounders are reliable and I learn how to use it properly, of course I would trust it.

 

[mvweebles]

AlexF - you bring up a good point. Rather, I'd say you need to use all the tools available and adjust accordingly. While I have been in pea-soup fog, it's been rare. I recall exiting Ventura Harbor at around 4AM with fog to the deck and darkness too. Radar was much more useful than chart plotter. I would not have exited without radar. As far as just plain darkness, combination of ATON, radar, and chart-plotter (and/or chart); roughly in that order. Personally, at night, I think it especially important to spend more time looking out the window at ATONs (at least in a channel) than the chart plotter. Maybe if I were a pilot with instrument certification I'd have a different opinion, but I'm not.



I am just finishing having a Simrad setup installed with their lower-end forward scan tranducer. Was about $700 to add to the system with minimal add'l install cost due to other activities.



Here's a decent amateur review. First 5-mins is install, so fast forward to actual usage - pluses and minuses. If you fast forward to around 10-min mark, you will see a split screen of forward-scan and chart plotter. The narrator doesn't mention it, but clearly the chart plotter shows 18-feet whereas the depth shows 30-ish feet. My use-case is to crawl to the front of the anchorage ahead of the boats with open running gear who are skittish.

Peter

 

[mdstrum]

Super Happy with Simrad ForwardScan ...have had 5 years...very helpful when anchoring (we can see it dropping and on retrieval, great for exploring shoreline's and coves for anchoring and scuba as well....ps we side scan and pair just amazing together!

 

[Slider70]

If all of your boating is done in waters that you know well a forward looking sonar may not be of much value to you?

I have commercial fished the BC coast for 28 year and now pleasure boat. I am often in waters that I have never been in before on my upper coast. Exploring in areas that I find interesting. After 28 yrs commercial fishing & another 27 pleasure boating I have found many rocks not documented on our charts, or charts with just plain poorly documented depths.

Some areas, ones not often travelled, can be particularly poorly charted once out of the commonly travelled areas. We even have some areas on the West Coast of the Queen Charlotte Island that are yet to be completely charted.

Last year I purchased a Garmin forward looking sonar and absolutely love it. Since then I have documented in one of my anchorages that the chart shows a rock right in the middle of the anchorage. It is not there. I suspected this for a couple of years but now know by spinning the boat around & watching the forward looking sounder. In another of my out of the way anchorages, which has a few challenging rocks, this sonar makes anchoring there much safer. Going through tight areas is now a dream.

Yes, if you are travelling fast it is not as useful unless you have someone glued to the screen. For gunkholing & slowly navigating tight places it is fantastic! And, yes I do like to anchor & explore where most folks avoid.

 

[HeadedToTexas]

I am about to install a Garmin PS51-TH. I had to wait almost a year for it. I will let you know how it goes!

Are you still going places? Will this quote email you about this watched thread? How about a review of the PS51-TH?

 

[HeadedToTexas]

Maybe I should just start a new thread, but the history seems important. Perhaps that history offers the best insight into the effectiveness of forward looking sonar. If it was all it was cracked up to be, everyone would be talking about it. Instead, 3 year old threads are all I find.

Still, I need to be convinced or convince myself. I get the 8-10 times the depth and 300 foot limitations of Garmin FrontVu (I have Garmin electronics). In open or known or trusted water, I cruise at 7-8 knots. If I were heading into an anchorage in Georgian Bay or working through a shoaled inlet on the ICW, I might be going 4 knots. 4 knots equals about 7 feet per second. If I'm in 10 feet of water and the FrontVu can "see" 8 times that far. I get depth and obstruction echoes 80 feet in front of the transducer. The transducer would be about 20 feet behind my bow, or 60 feet behind what the sonar can see. At 7 feet per second, I will cover that 60 feet in just over 8 seconds.

The image below isn't mine, but it seems representative of what I might have on my MFD in this situation. That seems valuable to me, though 8 seconds isn't much time. Am I reading that right?

 

[FWT]

I have Simrad and two transducers, one of which is Forward Scan.

At least in Simrad, one downside for me is something I never see mentioned.

Simrad can only run one transducer at a time. Normally for me that is a standard downward looking one.

To switch over takes a good half minute of changing plotter screens and punching buttons to activate the forward scan. At the moment I say to myself I'd like a peek at Forward Scan is also a moment I want to be heads up, not head down.

Its a training thing for me, and have not trained myself. Anticipate its use WELL in advance and get it set up before you need it, not once you need it.

I also have not taken the time to set it up better. The depth scale is set to some automatic feature so as you move, the scale moves, and the whole picture dances too actively. It pulls the eye down and focuses the brain too much on constantly interpreting the one screen. Next season I want to find a setting to fix the depth scale so that the dancing stops and a glance down is enough to tell me what I need to know.

Bear in mind I am on the Chesapeake where the use case is shoaling especially when entering small coves that often have narrow dredged entrances. Once you start your entry up a marked channel you need to keep your eyes on markers or position within the channel on the plotter, zoomed in. Interpreting a dancing Forward Scan moving depth scale is a distraction.

And yes, one needs to be moving quite slowly to have sufficient time to react to what you see ahead. In a spot where "deep water" might be 8 ft. the distance seen ahead isn't much.

On the Chesapeake we do not have deep coves with rocks in the middle providing a distant view with sharp depth contrast. There MIGHT be old duck blind pilings below the surface but I have yet to be in a place where that was a plotted risk so I can't opine on how well the transducer picks those up.

In deep water well into the Chesapeake there are numerous plotted obstructions in 25 ft of water or more. Its easy to become casual about them, but don't. Last summer I was heading north and cutting the corner of the south side of the Potomac entrance, to head toward an anchorage. There is a large fixed marker on that point, but well into the channel on the deep water side of the marker there are a handful of obstructions marked on the chart. On the deep water side of a marker by 50-75 ft those would be easy to ignore. I was steering a course to avoid them, thankfully, because as I passed them I saw they were pilings just below the surface just visible in the trough of waves. Within a deep water channel. Thankful also they were accurately placed on the chart.

The point being, being able to run both downward transducers as well as forward ones might be good at times, but that would also clutter the plotter with a dedicated forward scan panel. Information overload vs KISS.

 

[l00smarble]

I am currently installing a Garmin LiveScope LVS32 thru-hull system on my Selene 47. With a very deep draft I wanted the best possible information in shallow water. I was going to do the LVS51 but spoke to my insiders Garmin about the application on full displacement trawler and they suggested that the PS51 was a product just made to put something out to compete with Simrad/B&G forward scan and that all it does is give a rudamentary forward contour. See the "brown blob" in the sample photo above. They suggested they have better imaging systems for forward looking such as the LVS32 which is available in a thru-hull form factor.

I decided instead to install the LVS32. It has the same very narrow horizontal beam angle, better vertical beam angle, and rather that a brown blob you get highly detailed live "scanning" imagry. There are still limitations for how far forward it can look but I figured why get the blob when you can have more detail.

For example a stump or log should be much more identifiable.

I understand the value of this sonar will be limited but when I need to go nosing around looking for the center of a narrow, shallow channel or dead slow poking around to see if I can make with when cutting it to the last inches.

 

[twistedtree]

I am currently installing a Garmin LiveScope LVS32 thru-hull system on my Selene 47. With a very deep draft I wanted the best possible information in shallow water. I was going to do the LVS51 but spoke to my insiders Garmin about the application on full displacement trawler and they suggested that the PS51 was a product just made to put something out to compete with Simrad/B&G forward scan and that all it does is give a rudamentary forward contour. See the "brown blob" in the sample photo above. They suggested they have better imaging systems for forward looking such as the LVS32 which is available in a thru-hull form factor.

I decided instead to install the LVS32. It has the same very narrow horizontal beam angle, better vertical beam angle, and rather that a brown blob you get highly detailed live "scanning" imagry. There are still limitations for how far forward it can look but I figured why get the blob when you can have more detail.

For example a stump or log should be much more identifiable.

I understand the value of this sonar will be limited but when I need to go nosing around looking for the center of a narrow, shallow channel or dead slow poking around to see if I can make with when cutting it to the last inches.

View attachment 170345

View attachment 170348

I think we will all be very interested to hear how it works in real life.

 

[HeadedToTexas]

I am currently installing a Garmin LiveScope LVS32 thru-hull system on my Selene 47.

Very interested. And it sounds like the LVS32 solves FMT's issue of one transducer at a time by also providing vertical depth data, true?

 

[l00smarble]

Very interested. And it sounds like the LVS32 solves FMT's issue of one transducer at a time by also providing vertical depth data, true?

The one transducer at a time is a Simrad MFD limitation. The LVS32 has a "black box" sounder so it is a network device and will be always available to any MFD on my network regardless of other transducers.

So no it would not solve HIS problem as he has a Simrad system. But the same problem will not exist for a Garmin user.

 

[HeadedToTexas]

The LVS32 has a "black box" sounder...

Ah yes. Does the PS51 connect directly to a Garmin plotter or is it also a black box device that gets networked in?

 

[twistedtree]

I have been really pleased with my search light sonar. The ability to sweep from straight down to straight ahead gives a good look a the bottom contour below and ahead. It still has its challenges and limits, as all devices do, but I find it really useful. I think it's value is directly proportional to the effort you put into learning how it works, and practice reading the results.

 

[HeadedToTexas]

I think it's value is directly proportional to the effort you put into learning how it works, and practice reading the results.

Like so much in life!

 

[MYTraveler]

looking for a reasonably priced solution for checking structure ahead of the boat while anchoring etc.

there seems to be new advancements specifically with

ActiveTarget™ Live Sonar | Lowrance USA
in scout mode.

transducer may be lowered down and pointed forward as needed via a yet to be designed gadget

Any thoughts?

I have something like that on my bass boat. Mine operates at about 1 megahertz and has amazing resolution -- you can even see a fish's fins. It works best when the boat is stationary, but it is still great at up to 4 mph, as long as the transducer is pointed in the direction of travel. Its limiting factor is the range -- 100' is a stretch. Mine is made by Humminbird and Garmin makes something similar. Those two brands probably have 90% of market share and are regarded as a head and shoulders better than competing products (although for all I know, Lorance has caught up). You should check those out. On my big boat, I have a real searchlight sonar that works up to about 10 knots and has an effective range, depending on conditions, of about 500'. Its resolution is poor, but it is good for finding fish and structure.

 

[l00smarble]

I have been really pleased with my search light sonar. The ability to sweep from straight down to straight ahead gives a good look a the bottom contour below and ahead. It still has its challenges and limits, as all devices do, but I find it really useful. I think it's value is directly proportional to the effort you put into learning how it works, and practice reading the results.

What model are you using? These are generally large, commerical grade systems. Do you run with the sonar head deployed all the time?

 

[KnotYet]

Ah yes. Does the PS51 connect directly to a Garmin plotter or is it also a black box device that gets networked in?

I'm considering this model but haven't bought one yet.
I works directly with the latest generation of Garmin MFD's but earlier units require a 'box'.

 

[twistedtree]

What model are you using? These are generally large, commerical grade systems. Do you run with the sonar head deployed all the time?

A Furuno CH500. And yes, it takes up space and can be difficult to find a suitable location. I only deploy it finding my way into anchorages. They are mainly fishing devices and meant to be deployed while underway, but I use it for close-in navigation. In increased draft a bit, so could make sneaking into very shallow spots more difficult rather than easier.