Transducer position

[bijou22]

I have just purchased a Lowrance X67c fishfinder and the instructions say that the transducer must be positioned so that its centre is level with the water line. This will be almost impossible, as weight inside the boat changes,especially when travelling at speed. Can I just put the whole thing under the water line in a suitable position. Any recommendations would be appreciated.

 

[cp]

Re: Transducer position

IMHO they mean that the transducer must be parallel to the waterline, such that the transmitted pulse is sent straight down under the boat rather than off to either side as would be the case if the 'ducer were tilted (not parallel). The 'ducer must be immersed in water to work properly so having it level with the waterline does not make sense as you've already deduced. Good luck.

 

[Silvertip]

Re: Transducer position

Envision an upside down ice cream cone. That represents what the cone the transducer transmits. If you tilt the transducer you tip the cone so the transducer must be in the water and positioned so the cone shoots strait down. After all, you want to see whats under the boat right?

 

[Boatist]

Re: Transducer position

The transducer can not be near the water line if you want it to work right. The normal way to install is to the port side of the engine about 8 to 12 inches away. Make sure nothing ahead of the transducer to put air in the water, like a row of rivets or a hull stake.<br /><br />Then mount where the center line of the transducer is below the line of the hull. What this means is use a yard stick against the hull pointed to the bow, now mount the transducer where the top of the yard stick will be even with the center of the transducer. For best high speed this yard stick should be on the deeper side of the V Hull. Also with the boat on the water the transducer should point straight down. Do not match the angle of the V and point to that side. The angle fore and aft should be level or up to 2 degrees foward running on the water. This keeps the bottom of the transducer in contact with the water. Since this is very hard to messure about all you can do is think about how high your bow raises when under way and try and adjust transducer angle so it will point stright down at that time. For low speed operation it can be way off and work good but as speed increased then it get more critical. At high speed you do not want the front of the transducer lower than the back because it will create turburlance. If the back is slightly lower than the front it just keeps good contact with the water. On most boats if you put it level with the bottom of the hull that works great becuase when the bow rises the back of the transducer will be deeper than the front.