Topic: Helix 5 si-gps - transducer mount with i/o drive

[mckeapc67]

I apologize if this is a frequently asked question, but I didn't see a lot of information pertaining to this in other threads.

Can anyone provide their experience with mounting their "XNT 9 SI 180 T" transducer on the transom on a boat with an inboard/outboard?

I am considering mounting options for my transducer and don't want to waste time and effort mounting on the transom if it won't work properly.  The options that I'm considering right now are: (1) transom mounting to the starboard of the drive or (2) trolling motor mounting on my bow-mount.

I've done some looking at the transom of my boat and believe that I can mount the transducer so that it is just below the bottom of the I/O drive and about 12-15 inches to the starboard.  If I go any further to the starboard, it is clearly getting above horizontal to the bottom of the drive.  If I mount in this position with the transducer level with or just below the bottom edge of the transom, it looks like it should be able to see the port side without the drive being in the way (at least when not trimmed completely down).

I know the other option for a transom mount would be to use two transducers with a "Y Cable". to provide port and starboard views.  This may be an option later; but, I want to avoid the extra expense for now if I can.  As stated, my present fall-back would be to use a trolling motor mount which would mean not using the unit when the trolling motor isn't deployed (except, maybe for navigation).

Has anyone had a similar experience that can provide advice.

If it helps, my boat is a Maxum SR2100 bowrider with an Alpha-One out drive.  I'm also planning to use a stern saver mounting board as to not have to drill the transom.

[Bob B]

I think you have it figured out the best you can .... using some sort of method to test mount the transducer before doing it permanent may save you some holes and grief.

[Spd 135]

Hey neighbor, I can take a look if you want.  Mark

[mckeapc67]

Thanks for the replies. 

I think what I'm going to do is move forward with mounting the Stern Saver and transducer where I noted above and give it a try.  If it doesn't work, I'll get a trolling motor mount for now and use it on the trolling motor (or just focus on the imaging that it does provide.

Mark, good to meet another local on the board.  This is my first fish finder for my boat and I decided on the side imaging as a way to see more of the bottom and areas in Lake Pontchartrain.  Since you, obviously, use a side imaging unit, maybe you can give some tips and info on your experience in our shallow lake.

[mckeapc67]

I do have a couple of other questions regarding the install, though:

1.  If my motor/outdrive does partially block the port side, what would I see on the side image?  I would expect a bright line in the water column near the top (for the hard return at <2 feet) and also a shadow on the left (port) image.  I would guess the shadow would be way out to the left (port) depending on how much of the beam is blocked.  In my case, I'm hoping at worst that only the very near horizontal portion of the beam would be blocked.  Is this accurate?

2.  I know that Humminbird says that the side imaging provides 180 degree coverage, but in actuality, how close to a true horizontal beam is produced?  Does the 84 degree beam start at vertical (straight below the boat), horizontal (parallel to the water surface), or somewhere between?

Thanks, again for any inputs.

[rnvinc]

The outdrive can indeed create a "hard return" parallel to the centerline in the SI image ... (You can see a hard return obstruction just to the right of the SI image centerline in this image) ...



And the obstruction can create "darkness" at the outer edge of the SI image ... How far the "darkness" extends toward the water column is determined by how much of the SI sound pulse is being blocked by the obstruction ... (Left SI blockage can look like this) ...


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The "cartoon" advertising diagrams of SI coverage are very misleading ...


The 86° spec shown in advertising is where the sound pulse strength is measured not where the sound pulse stops ...

The sound pulse continues way past the "measured" angle spec ...


Rickie