Pointing The Transducer High

[ilk fish]

Hi Fishraiders

Has anyone experimented with pointing the transducer of a fishfinder higher,

for example 45 degrees up and to the side of the boat, so as to see any

fish way out to the side of the boat, it would be handy for trolling for kingfish at the

edge of a bombarah etc.

possibly something like hummingbirds side imaging sounders,

does anyone have any ideas on this.

regards ilk

[Josh88]

I'm not 100% sure but i dont think it'll work as the transducer needs to be parallel with the bottom in order to pick up a clear and accurate reading. If it was pointing out the side it would be a bit confusing to view if it did actually work. Probably better off just sounding directly down and watching the depth.

[caine]

yeah mine doesnt work like that

[netic]

The transducer wouldnt work properly pointed out to the side....

In order for a transducer to work it sends signals to the sea floor and then those signals bounce back to the transducer hence giving you the reading....what your describing would not allow the signals to bounce back...

and also, you would never have an accurate reading of the depth due to the angle

[volitans]

The transducer wouldnt work properly pointed out to the side....

In order for a transducer to work it sends signals to the sea floor and then those signals bounce back to the transducer hence giving you the reading....what your describing would not allow the signals to bounce back...

and also, you would never have an accurate reading of the depth due to the angle

Actually netic it would still work albeit at a reduced efficiency.

Its been over 35 years since I was trained as a naval rating specialising in sonar (UC - Underwater Controllers we were called) so don't ask me for exact figures of speed of sound underwater but in a nutshell all a sonar does is send a concentrated sound wave out from the transducer and listens for it's echo (hence the nickname 'echo sounder'). Our naval systems consisted of a 'segmented/multi directional' transducer while a modern sounder like those we use in our tinnies and so forth are uni-directional and some, (side scanning sonar) have multiple transducers. The direction a single tranducer is pointed is irrelevant. The sonar sends out a pulse, measures the time it takes to receive the echo and mathematically calculates the distance from the object from which the echo came.

There are variables that need to be accounted for such as water temp, inversions (ie cold water layers over warm), backscatter from impurities in the water, salinity, double echoes, sound wave frequency etc but if you send out a pulse say, sideways in a steep rock sided canyon, and receive the echo the sonar will tell you the distance from the transducer to the rock walls but not the depth. Echoes are deflected in ALL directions so while a pulse might hit a solid rock floor at an angle, sufficient reflection of the sound will be received to allow the sonar to work.

Hope this helps explain it. I could tell you heaps of stories about tracking subs, navigating channels etc but "Sea Patrol" is on and I want to finish watching it.