Forward pointing sonar devices for boats?

[GoingWalkabout]

Originally Posted by wrwakefield

Hi Chaya,

The 4G radar [software] is capable of using two separate radar scanning ranges [each with their own 10 MARPA targets...] [See the 2nd pair of photos on this page...] Also see early Panbo article when 4G was first released.

We do set up 'intrusion' Guard zones [i.e., something entering the established zone; you can also monitor for something leaving the zone...] on our radar for close range detection and have pretty good success with it. e.g., We have detected floating logs- especially when a few birds are roosting on it... [We even use the Guard Zone function as supplemental anchor alarm when close to shore since you can customize the shape of the zone... The 4G uses so little power this is easily justified.]

Regarding sea state detection and filtering, we haven't been in anything larger than 2 meter confused and refracted swell since we installed it last year, and it handled that well. However, I was too busy steering to play with detecting any unidentified objects floating in that mess (it did display the only other vessel quite clearly...)

Independent of the radar capability, we also really enjoy having multiple screens [we use iPads] showing the 'master' plotter/radar screen. [Using the GoFree wireless system.] You don't have to take your eyes off of everything when those needs to go below deck during watch arise. And, if the guard zone alarm goes off when being used as an anchor alarm, I just pick up my iPhone and check the radar screen without getting out of my bunk to perform the initial assessment- and mute the alarm.

I hope this helps describe the versatility available for your given needs.

Cheers!

Wonderful Bill. Thank you so much. Looks like 4G radar is the way to go. Ive looked at the new B&G. What do you think of their set up?

From my research even the best sonar can't get the forward distance that you can get with radar. 3 times or even 4 times boat length front imaging is way too close to an object when plowing through the seas. So I am absolutely convinced that radar is the best way to go for logs, containers etc. Im going to do further research on the current radar technology to see if things could be improved. Being an inventor and high tech manufacturer, when I am motivated I love too look at how to improve on what is out there. Mind you if the better mousetrap is already here great and if the guys doing it now are working on improving what they now have to being even better all the more better.

I may try and have a chat with the B&G radar tech guys. But in the meantime will look at putting in multiple screens with 4G radar.

Given my love of electronics I am planning on over specifying my solar build for my cat. Looking at 350 W per panel panels and as many of them that I can get on the back of the boat.

Again thanks Bill. Your first hand user information is fantastic.

regards,
Chaya

[Polux]

Originally Posted by svlamorocha

I have sailed a lot on a boat that had an Interphase forward looking sonar unit and thought your intended use was the only useful application I could find for it.

Only caveat is that the distance to the wall should not be greater than 3-4 times water depth.. This may mean you have to get very close to the wall before turning back to do the stern-to maneuver. Why not install it in the stern?

Yes you are right, why not in the stern? I thought that it would be useful also for slowly exploring an anchorage.

[GoingWalkabout]

Originally Posted by poiu

Here's are links to the B&G forward looking sonar. US and UK pricing. Miles apart as usual. Rip of Britain. (Little rant now over). It seems to be finally available now after much delay and cheap as chips at $699. It looks promising. I'm not too sure I'm happy to have the thing drag through the water though. It pokes down a bit.

ForwardScan UK
ForwardScan US

Thanks Poiu

[HankOnthewater]

Thank you Walkabout for starting this thread.
I think there are 2 issues here, both may need separate equipment/technologies:
1. Discover when a seabed is rising before your boat hits it. This is the realm of sonar, interphase looking forward stuff. I have never used any of this.
Not sure if items like submerged containers, whales or sunfish can be picked up with this technology.

2. Discover something that floats, like craypots floats, or again containers.
Possibly radar would be best for that. A large radar tweaked for close range ie 0.1 NM can pick up floats, birds. When alarm is set this can be used day and night. When using (Raymarine) 12KW with large open array, mounted ~3.5 metres (11 ft) above water surface, it can pick up floats as from approx 20 cm. I doubt if radar at the back of the boat (oops “aft, on the stern”) or radar mounted high on the mizzen mast would be much help here.

FLIR as Wakefield suggested? Have used them too, on sea rescue boats, at wide angle the resolution is poor at a distance, OK for 10-20 mt away. Otherwise difficult or impossible to pick up floats, unless one keeps watching the screen 100% of the time.

However big radars, powerful transducers, large screens etc. consume multitple amps..... Therefore one needs many hundreds amp/hrs of batteries (?1000 amp/hr or more), or run a genset, or....get another power source.

If anyone knows an effective way of detecting lobster pot floats (low angle radar infra-red range finder?), please let me know as we have serious problems of yacht entanglements with pots here on the West coast of Australia.

by Klaka

Yes Kim, I sail in the same area, a good lookout can pick most of them during the day. But in choppy seas or at night time…….. best remedy is to have a long keel and rudder on the back of it, then none of the craypots worry you anymore.
-grin-

[MYTraveler]

Originally Posted by HankOnthewater

Thank you Walkabout for starting this thread.
I think there are 2 issues here, both may need separate equipment/technologies:
1. Discover when a seabed is rising before your boat hits it. This is the realm of sonar, interphase looking forward stuff. I have never used any of this.
Not sure if items like submerged containers, whales or sunfish can be picked up with this technology.

2. Discover something that floats, like craypots floats, or again containers.
Possibly radar would be best for that. A large radar tweaked for close range ie 0.1 NM can pick up floats, birds. When alarm is set this can be used day and night. When using (Raymarine) 12KW with large open array, mounted ~3.5 metres (11 ft) above water surface, it can pick up floats as from approx 20 cm. I doubt if radar at the back of the boat (oops “aft, on the stern”) or radar mounted high on the mizzen mast would be much help here.

FLIR as Wakefield suggested? Have used them too, on sea rescue boats, at wide angle the resolution is poor at a distance, OK for 10-20 mt away. Otherwise difficult or impossible to pick up floats, unless one keeps watching the screen 100% of the time.

However big radars, powerful transducers, large screens etc. consume multitple amps..... Therefore one needs many hundreds amp/hrs of batteries (?1000 amp/hr or more), or run a genset, or....get another power source.

by Klaka

Yes Kim, I sail in the same area, a good lookout can pick most of them during the day. But in choppy seas or at night time…….. best remedy is to have a long keel and rudder on the back of it, then none of the craypots worry you anymore.
-grin-

Good analysis.
Regarding concern #1 -- a rising sea bed, I believe that risk can be all but eliminated (at least for guys like me who spend little time in unknown, shallow waters) with a good depth finder, charts (at least in US waters), local knowledge, and visual clues. When that is not enough, I find my scanning sonar to be sufficient to complete the picture, and have used it for that purpose in the Gulf and San Juan Islands, the Sea of Cortez, and in the poorly charted waters of Puerta Villarta and other parts of Mexico.

Concern # 2 -- floating stuff, is the one I worry about most, and in my defenses include scanning sonar, 25kw radar, FLIR (the ptz version), and daylight observable visual clues.

Frankly, radar is my last choice for detecting floating objects. It has the power, etc., to consistently pick up a single bird, or a single little bouy, or anything else that presents even a small profile (at least at the kinds of "close" ranges relevant here), but my concern would be that in even slightly choppy conditions something like a log would be masked by surface clutter. Similarly with a shipping container (or upside down boat, etc), or at least if barely floating.

FLIR is good, day or night, because the surface chop, being all about the same temperature, really doesn't show up, but anything floating will usually have enough temperature differential to stand out, even if surface chop largely obscures it. But, as a practical matter, it is really tough to keep a continuous watch on a FLIR screen (especially when there is nothing to see) -- its much more difficult that watching directly.

Naked observations are good, but only during daylight. I do suspect that even during daylight, a difficult to see object will be easily missed as few watch standers have the concentration necessary to notice the kind of thing that RARELY occurs. (In offshore waters, we see a real floating hazard maybe once every 500 hours -- of course, who knows how many we don't see, but it can't be that many since we haven't hit anything yet.)


The In my experience, except in the roughest conditions, the scanning sonar is the absolute best SINGLE TOOL to pick up anything big enough to be a collision concern from at least 400' and more typically 800'. Traveling at 8.5 knots (my typical speed), that is at least 25 seconds warning. Importantly, the scanning sonar has an audible output that changes frequency based on contacts (it takes a little getting used to, but after a while listening to it becomes subconscious and second nature). The problem with it is the HUGE number of "false" negatives caused by (bait) fish that swim out of the way (just like birds do) at the last minute.

That said, I believe there is a synergistic benefit from combining all information sources. For example, after storms you know that the risk of floating debris is greatly increased in inshore waters. That helps to motivate watch standers to pay close attention in those circumstances. Similarly, birds and floating objects go together.

[Roy M]

I have an Interphase SE200C. This unit is several years old, and at the time was the best we could get for under $10,000. Interphase sold out to Garmin, and the expectation was that Garmin would bring out an even more powerful unit. Nothing so far. Still, in deep water I can get images of meatballs (schooling baitfish) and pinnacles as much as 1000 feet ahead. At the slip, in 20 feet of water, I can distinguish pilings and keels, as well as underwater isolated rocks up to a hundred feet away. I bought this system with the hope of its being capable of helping avoid deadheads (vertically floating waterlogged tree trunks), sleeping whales and partially floating shipping containers. I haven't put these to the test yet. Normally, I use the twin transducers (like small mammary glands) to scope everything forward of the beam of my boat. I use the vertical mode, primarily to see what's ahead. If I get a ping (or hear the alarm go off) I switch to horizontal mode to see the extent of the possible obstruction and figure out an escape. When Simrad comes out with a better unit than my older Interphase, I will convert to it. The Interphase feeds its own screen, but can also be viewed on one of the two video ports of the MFD, and can be included on one of the accessory screens of the chartplotter.

[David M]

The dome of a US military submarine is filled with dozens of transducers in a phased array that can pinpoint an objects vertical and horizontal bearing many miles away depending on the sound channels. This much about it is common knowledge and is not classified. In passive mode they can hear and get the rough range (by true bearing change over distance) and bearing of biologics and human made objects that make noise for miles around. In active mode they can get the same of objects that do not make noise. Active mode can give away a submarines position.

[Cadence]

Originally Posted by David M

The dome of a US military submarine is filled with dozens of transducers in a phased array that can pinpoint an objects vertical and horizontal bearing many miles away depending on the sound channels. This much about it is common knowledge and is not classified. In passive mode they can hear and get the rough range (by true bearing change over distance) and bearing of biologics and human made objects that make noise for miles around. In active mode they can get the same of objects that do not make noise. Active mode can give away a submarines position.

I mentioned the sub dome earlier that could probably find a hair on my ass swimming. I guess most can't carry one of them around. But with todays technology, who knows? It might be a 1" dome.

[GoingWalkabout]

Originally Posted by Cadence

I mentioned the sub dome earlier that could probably find a hair on my ass swimming. I guess most can't carry one of them around. But with todays technology, who knows? It might be a 1" dome.

I think I've worked out where to put the multi phase sensor dome on my cat but I'm having problems where to put the torpedo bays to launch those babies at the hair on your backside.

[Cadence]

Originally Posted by GoingWalkabout

I think I've worked out where to put the multi phase sensor dome on my cat but I'm having problems where to put the torpedo bays to launch those babies at the hair on your backside.

Make it a boomer and add silos.

[svlamorocha]

Originally Posted by GoingWalkabout

Wonderful Bill. Thank you so much. Looks like 4G radar is the way to go. Ive looked at the new B&G.

I thought that the Antares yard in BA had already installed any possible gadget that could be installed in a cruising cat but I was wrong. Imagine integrating target acquisition by radar with this:
The Ultimate PWC Repellent

[wrwakefield]

Originally Posted by GoingWalkabout

Wonderful Bill. Thank you so much. Looks like 4G radar is the way to go. Ive looked at the new B&G. What do you think of their set up?

From my research even the best sonar can't get the forward distance that you can get with radar. 3 times or even 4 times boat length front imaging is way too close to an object when plowing through the seas. So I am absolutely convinced that radar is the best way to go for logs, containers etc. Im going to do further research on the current radar technology to see if things could be improved. Being an inventor and high tech manufacturer, when I am motivated I love too look at how to improve on what is out there. Mind you if the better mousetrap is already here great and if the guys doing it now are working on improving what they now have to being even better all the more better.

I may try and have a chat with the B&G radar tech guys. But in the meantime will look at putting in multiple screens with 4G radar.

Given my love of electronics I am planning on over specifying my solar build for my cat. Looking at 350 W per panel panels and as many of them that I can get on the back of the boat.

Again thanks Bill. Your first hand user information is fantastic.

regards,
Chaya

Hi Chaya,

I like the B&G brand and chose it over some of the other Navico brands [Simrad, etc.] mainly for the 'Sail Steer' capability in the Zeus MFD line. Not that we race, but I do enjoy the option of being lazy electronics can afford us.

I will plan to do more fine tuning and observations this year [we should be back on the water by early May...] with the 4G to try and better understand its limits for the uses we have discussed.

It will be interesting to hear what you learn from your discussions with the 4G technicians.

Also, if you haven't already been following it, there is a somewhat parallel discussion also on this forum.

Have fun with your planning.

Cheers!

[GoingWalkabout]

Originally Posted by wrwakefield

Hi Chaya,

I like the B&G brand and chose it over some of the other Navico brands [Simrad, etc.] mainly for the 'Sail Steer' capability in the Zeus MFD line. Not that we race, but I do enjoy the option of being lazy electronics can afford us.

I will plan to do more fine tuning and observations this year [we should be back on the water by early May...] with the 4G to try and better understand its limits for the uses we have discussed.

It will be interesting to hear what you learn from your discussions with the 4G technicians.

Also, if you haven't already been following it, there is a somewhat parallel discussion also on this forum.

Have fun with your planning.

Cheers!

Hi Bill,

I've done some research on the FLIR. What a great system. Like having an eagle on your mast as your eyes. They have small to large with all kinds of models in between. The model you can synch with the radar sounds really useful. Now all ill need is a guided weapons system and ill be all Safe and sound

[GoingWalkabout]

Originally Posted by svlamorocha

I thought that the Antares yard in BA had already installed any possible gadget that could be installed in a cruising cat but I was wrong. Imagine integrating target acquisition by radar with this:
The Ultimate PWC Repellent

What a great addition. Sidewinder on a Cat. As your article says its perfect for waters infested with Pleasure Water Craft. I think I could put 2 on the 560 Lagoon.



We tested our weapon at an undisclosed area along the Southern California coast. The area was heavily "infested" with PWCs, and was a perfect proving ground.


As soon as we set sail, a PWC immediately crossed our bow.

The targeting system immediately acquired the target and the missile was launched. The tracking capability of the weapon was impressive.




A confirmed kill.

As we passed the explosion, we assessed the effectiveness of the weapon, which was nothing short of amazing. The PWC had been reduced to some flaming wreckage at the intercept site, which was surrounded by a 500 yard "debri field" being rained upon by burning bits and pieces.
Test #2





Our second test was performed with the objective of assessing the long range capabilities of the weapon. The "Crispy Critter", skippered by Frank "Nine Fingers" Pineau, was stationed in the targeting zone as an observer craft.

With a PWC sighted off of our port bow, and Frank to starboard, we acquired the PWC and fired. For reasons not entirely known, Frank decides to light up a cigar.

At this point it was apparent that the tweaking of the missile's heat seeking sensitivity was to be our downfall. Frank starts shouting and waving his arms madly, the whole time holding the lit cigar in his hand.

Sorry, Frank.

Other than the part where we blew up Frank's boat, our experience with the AIM-9M was overwhemlingly positive. Frank was able to jump clear just before impact, and was quickly rescued. Due to the extreme heat detection sensitivity required to target PWCs, considerable care should be excercised regarding the environment in which these weapons are used. Nearby barbeques or cigar smoking sailors can quickly interfer with targeting. Nothing ruins a nice shrimp barbeque quicker than an incoming errant missile. In our case, we blew up a Hobie 16, scorched a perfectly good Hobie baseball cap, and hopelessly "soiled" a really nice pair of burmuda shorts.

It appears that when launching a Hobie in an area infested with PWCs, the most effective configuration is 2 of the missiles. The first is used early on, and the second is retained for the "deterrent effect". We noted that upon striking the first target, the remaing PWCs fled in short time.