Humminbird Side Imaging

[Hooksetter]

Here's a 2-part  question for all you guys using a Humminbird Side Imaging Unit:

Where do you have it installed, bow or helm? Why?

Hooksetter

[BryanP]

At the console, mainly because I do most of my looking while idling around.  Especially on Erie and LSC.  However, the guys who are using it on the trolling motor absolutely love it.  You just have to understand the limitations on the trolling motor. 

If you only have one SI unit, I'd definitely mount it on the console.

Bryan

Humminbird Rep--Michigan

[cr]

I've got mine mounted at the console , so I can use the GPS to find the way-points after marking them on SI . I try to cover the area I want to fish in a grid type pattern and mark what I want to check-out . I'd like to have one on the TM , just to help stay off the spot I'm fishing , but know where its at when trying to fish the back or side's .

[thedude]

mine will go on the console - as most have said, use it to find structure/fish as you idle through areas. From there, i have a 'bird up front linked in through the interlink system so i can mark waypoints on the SI unit and see them while on the TM unit (which is not an SI).

[5alive]

Where are you guys mounting the antenna?

[VinceR]

My 997 is mounted on the console. I surface mounted the antenna on the horizontal gunwale surface above the transom, about 15" to the left of the outboard. This where the antenna for my Eagle unit was mounted and I never had any issues with this location. I initially used this location, due to the fact that it is as close to being directly "above" the transducer, as possible (minimizing the position offset between the transducer and GPS antenna).

[cr]

I bought a ram mount that has a spot for the antenna on the same place that the unit mounts on , less holes in my boat .

[Cy]

Currently I have my Lowrance GPS puck located near the drivers console and the head unit.  I was planning on moving to the new puck to the back of the boat when I stall the 997 to be closer to the transducer and more accurate.

Does having the GPS puck close to the transducer improve way point accuracy?

Cy

[rustydog]

Well I did it, ordered a 997 yesterday. Just have to wait until May 1 to pick it up.For that much money it better put the fish in the boat by itself. I thought it was a stretch when I paid 1200$ for my Lowranace. Oh well its only money.

[Dan]

When I was at the Lowrance school recently, they talked a good deal about antennae placement. I know it's not a Humminbird, but antennae placement wouldn't really matter when it comes to best info.
The recommended placement was the bow. There was some very good argument for it, and I know from my own experience when you are moving around looking for a bed and the boat is pivoting on a spot with the antennae at the console it doesn't show much movement even though the 21 foot boat does a 360. I don't have my notes handy from the class, but I do recall there were several reasons why Lance Valentine, the instructor who guides for a living, recommended the bow.

[thedude]

in the case of the SIs however, you can scroll over the structure 300' to the left of the transducer and mark the waypoint... so it is calculating the distance from the transducer to the cursor in relation the antenna... if you have a 20' boat w/ the antenna at the bow and transducer at the transom, i would expect your waypoint to be 20' off.. unless you approach the waypoint from the same bearing as you were travelling when you originally marked it. Gps should be accurate to within in 5'-10' anyway.

[Hooksetter]

Thanks for the info! Sounds like the way to go would be a Si unit at the helm linked to another Humminbird at the bow.

Hooksetter

[Cy]

Dan,

I am interested to hear more about why the GPS Guru thought the puck should go at the console.  Can you check your notes and post a couple?

Dude,

If I am thinking about this correctly, the SI unit draws straight line perpendicular to the boat out each side.  You can then arrow over and mark a way point on an object.  The only calculation is how far is the boat to the object in a straight line.  The distance to that object is almost the same from the middle of the boat as it is from the back.  Think back to high school geometry and the Pythagorean theorem, A2 + B2 = C2, 2=squared.  If the object is 10ft from the transom, the transom is 10ft from the GPS puck.  You can make a triangle out of it and figure that the object is about 14ft from the puck.  A 4ft difference with GPS + or - 3 meters, is 4ft enough to make a difference?  I'm not sure?

If I move my puck to the back I have to find a spot where it won't be stepped on or kicked all the time.  I don't know what to do at this point.

Cy

[thedude]

i know what you're saying cy -
i don't think its really that big of a deal either, since there is not finite accuracy in the GPS itself... however, you still would have to treat the GPS antenna as an offset rather than use it to triangulate the waypoint.. because the unit thinks the transducer location and the Lat/Lon from the GPS are the same position. All the transducer can tell you is how far to the left or right the waypoint should be... so from there, everything else is calculated (i'm assuming) based on the gps position/signal.

if you have a 20' boat and the antenna/transducer are 20' apart, this would introduce a 20' offset in the waypoint vs. the actual location of the object. 3-4 meters is roughly 9-12'... so add another 8' to the radius around the waypoint to wherever the marked object might physically be...

again, probably not that big of a deal... it will still get you within 30', but if you're trying to mark a small rock pile or something, it might be a burden to locate it with a bait.

all that said, i will probably still mount mine near the console because its the easiest place to put it.