Furuno Navnet VX2 & SS264 performance

[leonidas]

I was wondering if you good people could give me some help/guidance with a couple of issues I am having with a boat, newly fitted, with a pair of SS264 transducers and a pair of Navnet VX2 units.
The setup was replacing older Navnet 1 Units and 600w Transducers.
The Boat has an ETR 6/10N sounder module, A Furuno Autopilot and FurunoRadar.

I have used the setup for a few months now and initially I wasnt very impressed with the performance until I was told to check that the Sounder module was switched over to 1kw rather than 600w.
It wasnt, and I opened the box and made the switch and the performace improved slightly.(hopefully I did it correctly)

My issue is with the correct setup of the transducers coupled with the Navnet VX2 units.

The setup does not seem to mark up individual fish (marlin/tuna), bait is showing up but I cant make out larger fish or really dont know what they will look like on these screens.

Typical water depths we fish in are between 40 - 200 meters. We look for bait and/or individual marlin/tuna around the bait.

In hindsight I should have gone for the newer Navnet 3D screens but I thought I would hold out until the newer models were released and tested in the field as I wasnt overly impressed with the performance of the Navnet 3D units on another boat.

Another issue I am having is with the colours on the screens. Both units, in the cockpit and the bridge, are set up exactly the same and yet the lower unit will mark up bait in red and the uper in black.

Over the last weekend whilst using the boat offshore I noticed that the GAIN I can use in the LF is basically Zero before the screen is filled with clutter. The HF is better but then I cant get it over 50%.
More than likely this is a setup issue as I have used a 585 before and didnt have the same probem.

Any ideas?

Any help or information would be greately appreciated.

Keep Smiling

Leon

 

[Snips]

Leon,
Thanks for your questions AND for adding a few screen shots so can better see what you are seeing. It is pretty clear from your pictures and discription you are dealing with turbulence going over the face of the transducers. You can see this in the amount of surface noice and gaps in your screen shots. Your upper shot showed that you were using 200Khz which works better in turbulent waters than 50Khz. The fact that even the 200Khz has gaps in the targets points to bubbles/turbuence. I can imagion that the both channels (50/200Khz) are pretty clear when the vessel is at the dock, but as soon as the vessel start to move the 50Khz side starts to get noisy and unusable, correct? If this is the case there isn't a setting in the sounder that can counter this issue.

Snips

 

[leonidas]

Snips,
Thank you for your reply.

Not surehow the post ended up on this forum, I meant it to go into The Navnet VX2/VX1 forum :questions

I understand the principle of turbulence on the face of the transducers, most likely on the day I took those images there would have been quite a lot of chop on the water.
Regardless, the gaps in the transmission are really not that big an issue to me as, when the boat is slowed down in those conditions the breaks are minimised.

The issue really is how do I read my screen, bait is easy, what about individual larger fish hanging off the bait? (marlin/tuna)

What is th eideal confoguration for this setup?

What about the issue with the differeing colours between the units?

Not being able to use more than 15-30% gain on either units?

Keep smiling

Leon

 

[Snips]

Leon,
If you can't operate the sounder above 10-30% gain that is the first issue you need to address. At the dock can you increase the gain without a problem?

Snips

 

[leonidas]

Snips,
Not at the boat at the moment, will check/test and get back to you next time I am there.

Leon

 

[leonidas]

Snips,
Finally Got back to the boat to have another look at the setup and play with the gain while at dock, as you suggested.
First I checked the transducers and can verify they are SS264 200 Narrow & SS264 50 Wide.
I adjusted the gain while at dock as the pictures show.



Shots of the settings

 

[leonidas]

Cont.

I also had an issue where the two units installed on the boat had exactly the same setup and yet had different colours showing for bait schools and bottom.
I adjusted the Echo Offset on the tower unit and found the colouts lightened up similar to lower unit.
Not sure what the correct settings for Echo Offset should be? Could you please explain?




That was the tower unit.

 

[leonidas]

Finally, this is the shot of the cockpit unit and its colours with Rcho Offset at ZERO.

I'm hoping this has given you som information to work with and give me some suggestions as to correct settings for the units.

Keep smiling

Leon

 

[Snips]

Leonidas,
Thank you for the screen shots. The fact you can turn the gain up to a higher level (at the dock) leads me to lean towards the transducer location being the primary cause of the degraded performance. Your first pictures showed close to three feet of surface noise and gaps in the targets which indicates turbulence/bubbles. Flush mounted transducers are more prone to turbulence than a transducer on fairing block. Unfortunately there will not be much you can do (setting wise) to combat this. Just so you know, the default TVG settings are 3 and your Echo offsets should be at 0. Do you have a picture of how the transducers are mounted?

Snips

 

[leonidas]

Snips,
Unfortunately without lifting the boat I cant get photo's of the transducer positions.
They are installed just forward of the motors, mid ship(Carolina Classic 28). I can get photo's from within the boat next time I am there and send them through if you like.

In regards to the turbulence in the initial photo's, the shots were taken on a fairly rough day so I would assume there would be more turbulance than at times when the seas are calmer.
Going forward I will drop off the first few meters as there will always be surface noise.

Regadless of the clutter and turbulance though, considering there is a set of SS264 1kw transducers mounted in the boat, it should be able to distinghuishe larger fish around the bait? :questions :questions
In regards to the TVG and Echo Offset (and other settings) where can I find explenations about their use etc. The manual for instance has nothing on Echo Offset. :huh

Keep smiling

Leon

 

[Snips]

Leonidas,
In the Customizing your Unit section of the Operators manual you will find explanations of all the sounders secondary functions, such as TVG and Echo Offset. If the goal is to see predators around bait balls you will probably need to use a lower Clutter setting. In the screen shots you sent you have the Clutter setting at 14, which is very high considering the setting ranges from 0-16. In most cases predators are smaller (weaker) targets than a ball of bait. It hard for me to say set your Gain at X and the your Clutter at Y without being on the vessel. But if you need have the Gain low and the Clutter high to help suppress to noise you are seeing then that needs to be addressed first.

Snips

 

[leonidas]

Snips,
would there be any benefit, with my setup(VX2), to going from the ETR 6/10N to a DFF1 sounder module?

Keep smiling

Leon

 

[Snips]

Leon,
Before you try a DFF1 and would like to see how your transducers are mounted.

Snips

 

[leonidas]

Snips,
When you say you want to see how they are mounted, are you talking about position in regards to the hull or how they are physically mounted?
The boat is in the water and only lifted once a year It doesnt get very cold here

I can take a photo from within the engine bay to show how they are positioned from within the boat but would have to wait till they are lifted before I can show position from the outside.
Both transducers are mounted just forward of the motors, midpoint of a Carolina Classic 28, if thats any good.
I have found a couple of photos of when the boat was lifted to get the transducers fitted
Originally it had a transducer with a fairing block as shown in the first photo, the SS264 is positioned in the same spot with the 2nd transducer in the identical spot on the other side.
The second photo is another shot of the hull from the front.
I hope this helps, if not I will take some shots next time it is out of the water, or from the inside if that is of any help.



The SS264 200 is a narrow beam and the SS264 50 is a wide beam.
Typically we fish in waters where we need to mark bait and marlin in water from 80 to 200 meters.
Would changing the SS264 200 to a wide beam be of much benefit??

Thank you again for your patience and help and knowledge :furuno

Keep Smiling

Leon

 

[Snips]

Leonidas,
Thanks for the pictures. It's really hard to tell from these pictures the exact transducer locations. When placing transducers on a "VEE" haul we would like to see them as close to the "VEE" or centerline as possible. This location places the transducer lower in the water and is subject to less turbulence than higher/outboard locations. You mentioned that you replaced a transducer that used a fairing block with the SS-264 in the same location. Can I ask if your sounder's performance increased or decreased after you changed transducers?

Snips

 

[leonidas]

Snips,
I didnt use the boat with the old electronics, I had them upgraded as soon as I bought the boat.
The transducers are mounted as close to the keel as is possible, you can get a rough idea from the photos.
In relation to turbulance, whilst hovering over bait I would guess there would be minimul turbulance (apart from rough days).
I have done this but still dont seem to arche up marlin around bait schools.
Hence the questio re the Wide 200khz transducer versus the Narrow.

Keep Smiling

Leon

 

[Snips]

Leon,
I like a wide beam 200Khz over a narrow beam. However if the screen shots you posted are typical of your 200Khz performance I don't think it will matter if you replace the narrow with a wide. The gaps you are seeing through the targets are being caused by turbulence and it will affect a narrow or a wide beam 200Khz equally.

Snips

 

[leonidas]

Snips,
The shots I posted earlier were taken on a fairly rough day, hense the gaps.
I am not as much worried about the turbulance or gaps as much as I am worried about target seperation.
There is not much I can do about the placement of the transducers on the boat, I just have to live with the gaps on the display during rough days. Using another transducer with a fairing block is not an option as it interfears with the running of the boat.
I wanted to know if going to wide and/or the DFF1 would enable me to "arch" bigger fish, like marlin, around bait schools as shown in my pictures.

Leon

 

[Snips]

Leon,
Arches are all about timing i.e. how long the target is in the beam of the transducer. The main parts to this equation are the transducers beam width, the vessels speed, depth of the target and how the target goes through the beam (center or off to side). Generally the deeper the target is the more chance it has to generate an arch. Notice I didn't say fish because almost any suspended object can create an arch. If your goal is to try to spot Marlin around bait I would recommend using as wide as beam possible and use both frequencies.

Snips

 

[leonidas]

Snips,
Would upgrading the sounder module to the DFF1 make any difference?

Leon