Is This Thinking TOO FAR Out of the BOX

[hardee]

Just wondering, IF this is way too crazy, or . . . ???



I am going ahead with a Raymarine upgrade which will include a new Transducer (RV-100), that will have RealVision 3D, CHIRP DownVision, SideVision, high frequency CHIRP, and 600W 50/200kHz traditional sonar.

What it doesn’t have are 2 important features that I am looking for, or use currently:
1. Real time, current (actual) water speed. (Have now via a paddle wheel on my P-66 Airmar transducer.)
2. Forward looking capability. Since I’m doing an upgrade, would love to have this capability without the HUGE transducer that hangs down under the hull. (Not something for a trailer boat.)

This brings me to two major questions:
1. To get water speed, I need to keep my old p66 transducer (Airmar). In doing that I lose the best place to mount a transducer, (between the down rotation side of my twin 40 Yami, and the inboard side of the trim tab,) not giving that spot to the new RV-100. Instead, the RV-100 RealVision 3D All-In-One Transom Mount CHIRP Transducer looks to be getting the second-best position, between the Twin 40’s, and just to Port of the cockpit drain hole. This will be about 10 inches from the Port side OB, and about 13 inches from the center of the Stbd OB and 16-18 from the up-rotation side of the prop.
Q #1. Does this sound like a reasonable plan to go forward with?

2. The Side scan 3D features reads to 300 feet each side, and down to 300 feet. So here is really where I may be so far out of the box I might be off on the next pallet (planet), but . . . . . . here goes - What if I fabricate a transducer mount that would allow me to rotate the RV-100 90 degrees(*) counterclockwise. That would let the starboard view then become a forward view, and allow me to look for bumpy hard things in my direction of travel when looking for some nook and cranny anchoring hole. (Please refer to the opening photo as an example.) This would be a manual operation, and only for 3 knots and under, mildly calm conditions, and would be for short term use only. AND manually changed back to normal position after anchoring, and that would show the anchorage, side to side.
Q #2. Does this sound anywhere near NOT CRAZY? Does it sound like a reasonable function for the fancy sounder version?

Well maybe more than two. :embarrased

Q #3. Is there anyone currently running more than one sounder transducer? If so, how far apart are they? Have you had any interference between them?

Q #4. Anyone here running twins, with a transducer mounted between the OB’s? Any adverse issues with that set up?

Anyone with any experience any way related to any of these issues, Please, speak up. I’m getting close to decision time here and this is a pretty major investment so I would really like to do it right and be able to move forward with a degree of confidence. I know the insight level of the C-BRAT community is WAY above normal so my trust level here is considerable.

Thanks for reading this far, and thanks in advance for any comments, negative or positive.

Harvey
SleepyC:moon

 

[ssobol]

Just wondering, IF this is way too crazy, or . . . ???



I am going ahead with a Raymarine upgrade which will include a new Transducer (RV-100), that will have RealVision 3D, CHIRP DownVision, SideVision, high frequency CHIRP, and 600W 50/200kHz traditional sonar.

What it doesn’t have are 2 important features that I am looking for, or use currently:
1. Real time, current (actual) water speed. (Have now via a paddle wheel on my P-66 Airmar transducer.)
2. Forward looking capability. Since I’m doing an upgrade, would love to have this capability without the HUGE transducer that hangs down under the hull. (Not something for a trailer boat.)

This brings me to two major questions:
1. To get water speed, I need to keep my old p66 transducer (Airmar). In doing that I lose the best place to mount a transducer, (between the down rotation side of my twin 40 Yami, and the inboard side of the trim tab,) not giving that spot to the new RV-100. Instead, the RV-100 RealVision 3D All-In-One Transom Mount CHIRP Transducer looks to be getting the second-best position, between the Twin 40’s, and just to Port of the cockpit drain hole. This will be about 10 inches from the Port side OB, and about 13 inches from the center of the Stbd OB and 16-18 from the up-rotation side of the prop.
Q #1. Does this sound like a reasonable plan to go forward with?

2. The Side scan 3D features reads to 300 feet each side, and down to 300 feet. So here is really where I may be so far out of the box I might be off on the next pallet (planet), but . . . . . . here goes - What if I fabricate a transducer mount that would allow me to rotate the RV-100 90 degrees(*) counterclockwise. That would let the starboard view then become a forward view, and allow me to look for bumpy hard things in my direction of travel when looking for some nook and cranny anchoring hole. (Please refer to the opening photo as an example.) This would be a manual operation, and only for 3 knots and under, mildly calm conditions, and would be for short term use only. AND manually changed back to normal position after anchoring, and that would show the anchorage, side to side.
Q #2. Does this sound anywhere near NOT CRAZY? Does it sound like a reasonable function for the fancy sounder version?

Well maybe more than two. :embarrased

Q #3. Is there anyone currently running more than one sounder transducer? If so, how far apart are they? Have you had any interference between them?

Q #4. Anyone here running twins, with a transducer mounted between the OB’s? Any adverse issues with that set up?

Anyone with any experience any way related to any of these issues, Please, speak up. I’m getting close to decision time here and this is a pretty major investment so I would really like to do it right and be able to move forward with a degree of confidence. I know the insight level of the C-BRAT community is WAY above normal so my trust level here is considerable.

Thanks for reading this far, and thanks in advance for any comments, negative or positive.

Harvey
SleepyC:moon

Couple of points:

Why do you need actual water speed? Isn't GPS speed good enough and more accurate regarding your actual progress?

Putting the transducer between the engines may limit the "field of view" and get reflections off the lower units. Not sure if this would be a problem or not.

When you look at a transducer trace, it is a generated image by repeated pings and returns as you move along. The image is basically a composite of a bunch of slices taken over time on a line perpendicular to the boat line of travel. It is not a snapshot of the whole field taken at once. If you rotate the transducer 90 degrees you are just going to get a narrow slice looking ahead. Since the plotter is expecting a series of slices over time that it sort lays in a trail behind the boat, the display will take some clever interpretation because the plotter is not designed plot information from ahead in the manner you are probably thinking. On most plotters the view to the front would be plotted as a strip moving from right to left. Also, running with the transducer at 90 degs to its design could create drag and turbulence that will degrade the returns even at low speeds.

You have to look at the angle the transducer shoots at. Even if the range is 300 feet, the downview angle may be only 30 or 40 degrees from center. In shallow water this is not going to look very far forward.

If you really want a front view display, I would buy one for that purpose and put it on a deployable mounting that you can lower when needed and retract (or remove) before trailering.

I've read of some fishermen who run multiple transducers for different conditions, but there is some way of switching which one is active and I don't think they operate more than one at a time.

 

[thataway]

Harvey, Thataway had two of the CPT-100D transducers about 8"apart on the Starboard side of the single engine. No interference, but I ran them on different frequencies. They are downscan transducers, but should work the same. You want the Real Scan transducers where they have good vision of both sides--Also turbulence of water from the props can be an issue.

I would put Starboard blocks on the lower part of the transom, and then you can screw the transducers into the blocks, you may need to move them periodically to get the best picture.

I don't think you are going to be happy trying to use "RealVision" transducers turned to read forward. Usually phased array transducers are used for forward scans. The Panoptic by Garmin is one of the better forward looking units. The bottom of the boat will interfere.

 

[drbridge]

In situations where you are doing 3 knt and looking for obstacles could you shut off and possibly lift the starboard motor to cut down on turbulence and provide a clear view for the transducer?

 

[mstrpo]

I was also looking for a way to see hard objects approaching instead of those I had already gone over. To accomplish this, I took a page out of the book that pontoon boats use for fishing and rigged a mount for an inexpensive fish finder transducer (still has CHIRP) for the front of our Tomcat. I mounted a pipe to the rail just offset of center (avoiding the anchor bow roller). The mount allows me to raise and lower the pipe. The transducer is mounted at the bottom of the pipe. The down pipe rests on the rub-rail in a vertical position. Note that I rigged this up to see how it would work and will need to make some changes for a better, easier to use mount and route the cable more appropriately.

This all works and gives me very accurate shallow depth and bottom image for slow speeds. When traveling over 10 kts or so, I go forward and raise the transducer out of the water.

 

[forrest]

I have often wondered how "sidescan" works when it has to look through a outboard motor shaft or the outdrive of an inboard. I've asked that question of factory reps in the Sportsmen Show seminars and have never received an adequate explanation. One rep stated that it looks a little forward. I then asked if it looks a little forward, how does it see through the keel of a deep v boat. Personally I'm very skeptical of sidescan. I just don't see how sidescan can see bait balls on the surface opposite the side your transducer is mounted on. Disclaimer: I have a Garmin unit with chirp and sidescan on my boat along with my original Furuno sonar. If I want to see what is really going on, I look at the Furuno screen.

 

[Robert H. Wilkinson]

What if I fabricate a transducer mount that would allow me to rotate the RV-100 90 degrees(*)

I see this as being a bit tricky. Most of my other concerns have been addressed by the previous posters.

If $$$ is of no concern 8) - you could install an electric bow mount trolling motor like the bass fishermen that can have a transducer mounted to it for forward vision. This would work for your low speed gunkholing. You can get self deploying models and it would only need to be deployed low enough for the transducer to be under water. Unless you planned on using the actual motor a lot you wouldn't need to buy a large one or invest in a lot of extra batteries. I have one(no transducer) on my 16' bowrider with a remote that I can control it with anywhere on the boat. They are nice for gunkholing and sneaking in on a fishing spot early morning. You can even get them with auto pilot and anchor modes. You could probably do the same with a cheaper transom mounted one if you didn't want anything mounted on the bow.

When we rented a houseboat(no electronics) I mounted a transducer to a pole and strapped it to the side rail. This allowed me to use my fishfinder for water depth. Worked ok as the top speed was only 4-5 mph. If you end up with an extra compatable transducer maybe you could rig up something like this and run the wiring to plotter when needed.

My plotter has an adjustable alarm that warns me if my course is heading towards an obstruction or shallow water but that is based only on map information and not a real world sounding.

All in all it would probably be cheaper to enlist an able bodied seaman - conning on the foredeck with a pole in one hand and a lead line in the other!

Good luck, and Happy New Year!

Rob

 

[jkidd]

Here's three as long as you are using different frequencies they will work if you set two of them to the same freq. you will see diagonal lines scrolling through the screen. The last trip to lake Powell I clipped a cottonwood tree with the forword sonar and it removed it from the boat. I just need to remount it.

 

[drbridge]

On our boat I installed a Garmin Stryker 7SV stand alone sonar/fishfinder. It gives much better feed back than the Raymarine DSM300 and Airmar PS66 combo that was origionally installed on our boat. This also gives redundancy for Sonar in case one of the systems fail. I like having the sonar on it's own 7" screen, leaving the Chart plotter screen open for maps and Radar. The Garmin unit sells for as low as $400 including Transducer. It has Side scan, although I have not found it to be useful and do not use it.

 

[C-Wolfe]

I might be even crazier then the OP but, what about mounting the transducer in hull under the v-berth. On my boat (2006 M Y), the wood core stop a few inches forward of the v-berth bulkhead.
On my previous sailboat I did install a very basic dual frequency transom mount model transducer in a big blub of silicon forward in the boat (had to go past the lead ballast) . That was just for basic deep reading at slow speed, but it work just fine for my need at the time.



Not very obvious but the wood core stop a bit aft of the edge of the shade. I could get better pictures if anyone is interested.

 

[smckean (Tosca)]

When you look at a transducer trace, it is a generated image by repeated pings and returns as you move along. The image is basically a composite of a bunch of slices taken over time on a line perpendicular to the boat line of travel. It is not a snapshot of the whole field taken at once. If you rotate the transducer 90 degrees you are just going to get a narrow slice looking ahead.

So well said. There is an important lesson here even for just plain ordinary depth sounders (not 3D).

I have keep reminding myself of this lesson nearly every time I go out. The plot from a depth sounder looks so much like a profile of the bottom that I sometimes forget that it is not. It is more like a graph of all the depths the sounder has seen recently. If you want to disabuse yourself of this common misunderstanding, drive the boat in a medium radius circle over sloped terrain sometime....you will quickly see the difference.

P.S. I do sometimes want a "picture" of the bottom when I look for places to drop crap or shrimp pots. Although a "picture" (like a topographic map) is not possible, a cross section (profile) of the bottom is. I slowly cruise the boat in a straight line perpendicular to the predominate slope of the bottom; the resulting plot is what the bottom looks as if I made a slice (to use ssobol's excellent word) along that path. (BTW, I once lost a $200 crab pot setup because I didn't understand this difference :? .)

 

[thataway]

I've read of some fishermen who run multiple transducers for different conditions, but there is some way of switching which one is active and I don't think they operate more than one at a time.

You can run more than one transducer at a time with two MFD--I have been doing it for years. Just use different frequencies modern depth finders make this fairly easy.

There is an important lesson here even for just plain ordinary depth sounders (not 3D).

This is true that it is in slices--even the 3 D, but the 3D integtration makes it look like 3D. Harvey is proposing "RealVision" transducer which does it all--traditional depth sounder "A"Scope. Down Scan and side scan--plus integration of all of these modalities and modalities: However this is mostly a historical trace--as are most all except forward looking sonars (the phased array's), It appears to "Look ahead" a few feet beyond the boat's bow, depending on the depth of the water. See Video link below/



Here is a video showing Side vision and the 3 D Real vision

Jody--you have a transducer mounted facing forward. I could not find your description of what you did--but I remember you did explain it. Can you refresh our memories?

 

[ssobol]

If you use a typical chartplotter and transducer and the boat is stopped, the plotter will display a moving trace on the display with a constant depth bottom. The same slice is being displayed over and over again but it will look like the boat is moving along.

 

[jkidd]

The current Garmin transducer is the ps22-tr it sees 300 feet in front and 300 feet down and is live sonar. It will show anything in it’s view down to fishing lures. Here is a link to the old thread.

http://www.c-brats.com/viewtopic.php?t=26691


The new Livescope product has got a little better for fishing and structure.

 

[texasair]

I have a 2nd transponder in hull mounted in front of the helm in the right hand v berth compartment. At speeds over about 18-20 mph it stops working as that part of the boat at those speeds begins to clear the water.
At any speeds slower it works great and I use in for nosing into shallower areas as it gives me about a 12-14' advantage over the rear one. It has helped prevent damage to my propeller on many occasions.
I mounted it to shoot straight down, in hind sight, I could of spent a little extra time to try it at a slight angle to look a bit more forward. before I glassed it in.
It is an entry level unit, But overall I am pleased with the additional capability.

 

[thataway]

Thank you Jody.

Jay had mentioned Cochise (Steve Dashew"s 78' power boat going up Maskill Harbor in Canada.

Here is the current link to that video. They are using Simrad forward looking Sonar in that case.

The material show that distance of view is: Nominal forward view of 4- 5 times your current depth Maximum forward view of 8 times your current depth. This is not unusual for forward looking sonars.

I am thinking about upgrading the electronics on the Caracal Cat. I am very familiar with the RayMarine (had on C Dory 25). Also Garmin--on the last 22. I have not used Simrad (Navico) since the Tom Cat--over 10 years ago.

I would say in is a "toss up" between Garmin Live view and Raymarine. The Caracal Cat has a bow trolling motor, but I don't keep it mounted all of the time. I probably will go with RayMarine. 3 D RealVision and a 9" screen.

 

[hardee]

Oh WOW, this is really great. Such good responses, and really exciting to see such good info. Hummmm, maybe more questions now, than answers, but thank you all for the input. Love it.

First, “why do I want real time water speed?” Because then I can tell if I am going “upstream” or “downstream” on the tidal current. Many places in both the San Juan's and north up along the coast in BC, in among the islands, it is hard to tell which way the current is moving unless you stop and watch the shoreline for your drift. Having water speed negates that stopping. It also helps when figuring the ETA for a destination at a given speed. My main use is for knowing what speed to use to maintain a given, static geo location (Boat is not moving relative to the nearby land – used in photography mostly). Can also be useful in calculating water miles versus over the ground (GPS) miles.


“Putting the transducer between the engines may limit the "field of view" and get reflections off the lower units. Not sure if this would be a problem or not.”
From what I have been able to read, the transducer will be behind, and angled slightly ahead of the OB leg, about 3 degrees forward of vertical.


“If you really want a front view display, I would buy one for that purpose and put it on a deployable mounting that you can lower when needed and retract (or remove) before trailering.”
That is a great idea but I do not want that forward facing transducer dragging in the slipstream on a full-time basis. And it is big. (See the photo on Jkidd’s post).
Jody, does the forward scan transducer have aa “kick up” ability?

“This also gives redundancy for Sonar in case one of the systems fail.”
That redundancy is also why I am looking to leave the P-66 on and usable. I like the idea of having a second transduce available."


“What about mounting the transducer in hull under the v-berth.”
This is also a good idea and one I have been considering for a while, especially if it is totally independent of everything else, only showing depth. An inside the hull mount will lose temp, and speed measuring capability. Mounted just forward of the forward cabin bulkhead (helm bulkhead) it would be ideal if near the center. I don’t think that is a crazy idea at all.


“ . . . lift the starboard motor to cut down on turbulence and provide a clear view for the transducer?”
Good idea, and could probably help. Might be the sacrifice in handling I will need to make for increased visibility below.


I am now understanding the “Slice” concept much better. Turning the ducer 90* and moving forward will be a very narrow real picture. Moving the boat across the opening to a tiny bay, may give a better picture, or finding a spot in the bay and doing a 360 rotation might be easier. Doing that with the Axium will allow marking the good anchor spot with a waypoint, and then just go to that. Maybe it will be that easy.

This is really educational. And I am learning.

Thanks for the clinic on transducer vision.

Harvey
SleepyC:moon

 

[jkidd]

Jody, does the forward scan transducer have aa “kick up” ability?

Yes it has a little tiny shear pin, but when I hit the cottonwood under the water it didn't break the shear pin, it pulled all of the screws out of the starboard mount. I also have one of the Livescope transducers that I mounted on a piece of pvc pipe and that clamps to a Ram Ball mount. It allows me to remove it or turn it or just raise it up out of the way. That will also give me the ability to turn the transducer to the Prospective mode and that gives you a 180 deg. image.

 

[Karl Konecny]

I also like a paddle wheel on my transducer for a speed signal for all the reasons Hardee mentioned. Out of curiosity, I compared my paddle wheel speed indication with GPS speed-over-ground. On a calm day on a calm lake I went back and forth at various speeds and recorded speed and SOG (I was also measuring fuel flow, rpm, etc. with a couple of propellors at the same time). I found that below hull speed, the paddle wheel indicated low. For example when SOG was 4.8 knots, the paddle wheel indicated 2.1 knots. When I was on plane, the opposite was true: the paddle wheel indicated high. For example when SOG was 18 knots, the paddle wheel indicated 23.6 knots. I still use both keep my custom calibration chart at hand.

 

[jkidd]

Harvey

They do make NMEA 2000 paddle wheels so if you put a NMEA 2000 network in your boat the new display will read that data. Then you don't need to save the old display.