Mounting Transducer 898

Have a new Humminbird 898 SI that I'm about to install on my boat. I already have another Humminbird that has GPS, but does not have side by side imaging. It is a very good unit, I like it a lot, and I am going to keep it on the boat. As for the transducer on my new 898 I understand that if I am travelling at speeds of something like 15 or 20 mph and over, the screen will not show the depth of the water or any other detail for that matter. (I know there is an adjustment to help with the refresh rate, but as you will see I'm not worried about high speeds.) My older unit does show depth at any speed. Seeing as how I will be using the 898 to locate fish I really only need depth/fishfinder while I'm travelling about 3 to 5 mph. So, with all of that, I am thinking of mounting my transducer of the 898 so that it is completely above the bottom of the boat. The transducer will obviously be in the water, and since I don't need any readings from it at high speeds this should be fine for my purposes, I think. The reasons I want to mount it so high is that it will be better protected, I won't have any rooster-tail issues, and it should give pretty good readings because it won't encounter as much turbulance.

What do you fine folks think?

As long as it is somewhere above your running surface and you at-rest loaded water line, it will be good to go. Do you have any idea what your t'ducer will "see" from its chosen location? There are some simple procedures for that before you begin chucking up your favorite drill bit.
Safe boating...

Good plan. Just make sure that the mounting location of the HDSi transducer doesn’t block either the right or left Si sonar. I think that this is what Captain Chris was hinting at.

Gansett, not sure where you got that information from. but, if I have my 898 on the 2d screen, I see bottom at 30+mph. I believe a lot of folks mount these HDSI transducers higher to help prevent damage to a struck object. When they are out of the water, you won't see bottom.

Thanks for the responses, folks. Stymie, I have been on several boats owned by others (4 or 5) who have Humminbird SI imaging and they all lost depth recordings at fairly low speeds. I guess it's the "second screen" thing, so I'll check that out. Based on what you said, I'll do more research and if I can get depth at high speeds I'll change my plans. Thanks again.

Stymie is right. The stock HDSi transducer that gets shipped with the 898 units is capable of high-speed depth readings but only if your boat hull will allow this. With the Si transducers you not only have to locate it in a position on the transom that has a constant flow of air bubble free water (which not all boats have); you also have to mount it in a location that will allow for unblocked left and right Si sonar. This is not always possible on all boats. Many install the Si transducers up higher on the transom or even on the jackplate to protect it from damage (the HDSi transducer is $250 to replace) and install a second transducer for high-speed water depth readings.