I am new to the forum and like most newbies I have numerous questions concerning the installation of the SI transducer.
I have a Nitro 640 with NO jack plate and the hull is stepped. I understand that if I mount the transducer on the transom as the instructions suggest, the motor will block the view on the port side. The other problem with this location is the position of the lift strikes. In order to maintain the 15 inches that they suggest, the transducer will be in the wake of the lift strike or in danger of hitting the bunk when loading and unloading the boat.
I have reviewed other posts and many suggest mounting under the jack plate. Since my boat does not have one, this eliminates this possiblity. Other posts suggest that the transducer be placed on the step next to the drain. I also like this idea, as the step on my boat is level and it makes sense that the transducer would get a good view from that location. I also think the transducer would be well protected from debris at this location. I am concerned about the turbulance that the main hull will create, however. Some of the posts suggest that this is a real problem but only at high speeds and suggest a second transducer installation to allow me to use the finder at high speeds. This makes some sense to me as well I guess.
I do have some questions though that I have not seen addressed in any of these posts. Humminbird has two flavors of SI transducers. The one that comes standard with the unit mounts to the transom or with an adapter can be mounted to the trolling motor. The other one is a thru hull version. It seems to me that the thru hull version would work best mounted in the step location. I have not seen anyone talk about this being a good solution here, however. I have also noted that the many posts covering this subject talk about issues with the transom mount version being set to the correct angle. I don't think the angle is adjustable on the thru hull version. That may be why no one talks about using this transducer at this location. So what is a guy to do?
If two transducers are the answer for my boat, do I need 2 SI transducers, or can the one that I use when running on plane be one without SI? If I need 2 transducers and both should be SI transom mount type, where do I place the one that I intend to use when I am running on plane? I think I have ruled out the transom idea earlier. A thru hull mount might work for this application, but as far as I know it is only available in a SI version. If SI does not work at high speeds, then what is the point?
I'll bet you have never met anyone who is so confused. I just want an installation plan that has a pretty good chance at success. I don't want to be drilling a bunch of holes in my hull trying tro make this thing work. I would greatly appreciate any help anyone can offer. I am really anxious to get this thing installed so I can get out there and give it a try.
I have attached a couple of photos that hopefully will help.
I also noted on the documentation I recieved from Humminbird that you can exchange your transducer for one that will work better with my installation needs and only pay the difference. Has any one been able to take advantage of this? I sent an inquiry email and have not heard back from them in two days.