Topic: Mounting on dual outboard boat

[TrickyRick]

Hello all    this is my first post here and am in the final days before pulling the trigger on a 898c SI unit.  My question is that I have a dual outboard SeaPro.  What has been the consensus on mounting the transducer on a dual outboard boat?  Another transducer on the other side?  Mounted in the middle?  Don't have a great picture of the aft end of the boat (at work right now...shhh ) but will try to get some this week.  The unit will be uses almost exclusively for SI and not depth as I have a Raymarine C140W with depth sounder module that works pretty well at planing speeds.  Another question...ares the 200kHz beams from the depth sounder module and the SI going to clash and give erroneous readings?

Best pic I have right now...you can see the existing transducer from my Raymarine on the starboard side.  Thanks!

[Wayne P.]

You can mount the SI transducer beside or just above the hull drain. You may have to keep the outboards trimmed out a little when scanning.

More than likely you will get cross talk on the 200 khz frequency. If it is a problem, you can just turn off the Ray Marine unit when you are using the 898.

[TrickyRick]

Yea that is what I was thinking...I have the dsm on a switch so this should not be a problem.  Thanks for the reply.  I think I will start with it there and see how it goes.  Most of the posts I have seen say you have to have the ducer kind of sitting in the water stream...is this not going to be an issue since I am not really using it for depth at speed, just trolling or searching for structure with SI?

[Jolly Roger]

Hi Rick and welcome to the forum!

I agree with Wayne about the 200 kHz about the disturbance issue, but I would rather turn off the Bird for high speed runs if the Ray is giving the better readings.

I have a dual engine boat as well and mounted my transducer in the middle of the outdrives. The distance to the propellers is about 36 cm.





The pictures and recordings are fine as long as I keep the revs down to 1500 rpm. Raising the revs results in disturbance on the pictures and recordings.


I've been out with my colleagues of the water police in the last weeks. They have a dual break through transducer set up on their boat.  I was amazed how good their pictures are even at high speed. Especially the 2d sonar is Cristal clear compared to my 981. I think this is because their transducers are far away from the propellers (approx. 4 -5 meters).

Thinking about it I realized that I had much better (clearer) pictures as well when I was using my tow fish. I will propably go for a new mounting position next year to get more distance to the props. I guess the props are producing noise in the frequencies the sonar is using and staying away from the source of the noise will give me better results.

Therefore:
Stay away as far as possible from your propellers.

Best regards and wishes

Harry

[TrickyRick]

Hey Harry , I read your original post about this issue and was hoping you would update me on what you did!  So if I am reading you right you think that two transducers mounted as far outboard of the engines the better?  Oh well its just money right?   

BTW my wife is in the Navy and I am retired.  We just transferred from Stuttgart to DC    Not sure where Lake Constance is though

[Jolly Roger]

You gotta be kiddin!!!

Where you been ? Panzer in BB or Patch in Vaihingen?
Been there a couple times and was planning to do some work with the Navy guys down here.

Lake Constance (Bodensee) is just 100 Miles down south. Follow the A 81 and you're at my place within an hour.
Small world  .

Regards / Harry

[TrickyRick]

She worked for Patch in Vahigen and I worked out in town for NATO.  You're right small world.  You ever get over here drop me a line and we'll fish the Chesapeake Bay for some 40# Rock Fish (also known as striped bass) 

[Jolly Roger]

Chesapeake Bay?
Ha! Been there in 92 on a boat ride from VA. Beach to Northfolk. What a ride!

Back to the topic:
I think Greg will comment on this later. The key to get clear pictures is to have the transducer in "clean" water. No bubbles or turbulences....

Having the transducer further away from the props is just another point from my "experience".  If I had the fish deployed, the picture on the screen was much clearer even if I had the revs up and the fish further away from the ground.

Another thing: Electronical / electrical interference.

Read about it here: http://forums.sideimagingsoft.com/index.php?topic=1753.msg9801#new

Make sure that you wiring is away from other electrical stuff. I'm also using a seperate battery to power my Bird.

The problem I have at the moment: Since I've been out with the guys of the water police and I've seen their 997 in comparison to my "old" 981, I'm about to sell my 981 and get a 997 or a 998. The other boat of the water police is at the work shop at the moment. It is equipped with a 998 and I'm looking forward to go out with them and see the 998 in comparison to the 997.
But first I have to get the X-mas presents for the kids......  .
And I don't think my wife knows how to read Humminbird on MY wishlist  ...........

Regards / Harry

[Humminbird_Greg]

Harry,
I see no need to comment other than to say that you guys have it all covered 100%!