The transducer was offset in both the x and y axis. It was actually pointing in the starboard-bow direction.
The bow-stern angle was offset with more than 15deg. This had me thinking:
I could always find reefs in 10-20m of water, anything above that I couldn't manage. Also, above that depth I couldn't really make out much detail.
I can count on my fingers how many times I could find a decent fish arch. I always thought I had a crap fishfinder or that I am just no good at getting the guys on the fish! (This may still be true however!!!!)
I know that a transducer emits a ultrasonic wave in a cone shape but lets narrow this down to a single line. Because the offset here will in my opinion have the same effect on a cone as on a straight line except the cone will suffer less from it.
Say I am searching for a reef in 15m of water, with an offset of 15deg on my transducer I will miss this reef with 4m. Fair enough.
Now in 40m of water this figure becomes 10m. This is now only for the one component of which my finder was offset.
I am also not taking into account the fact that it was mounted too high which meant I could never read the bottom while planing. The boat therefore was nose high up in the air and this will add even more than 15 deg to that figure. If I now think about what my boat is like just before plain I would say that angle is close to 40. In 40m of water that is 33m!
This is only be how much I will miss my target. I also don't take into consideration how much power/coverage I will lose from not having my transducer sounding straight down and receiving the signal straight up!
What do you guys think? Does this make sense or am I just talking nonsense?
The blue line is the depth line, the green line is the actual direction of the ultrasonic wave. The red line is the distance by which it misses the depth line at a certain depth.
The bow-stern angle was offset with more than 15deg. This had me thinking:
I could always find reefs in 10-20m of water, anything above that I couldn't manage. Also, above that depth I couldn't really make out much detail.
I can count on my fingers how many times I could find a decent fish arch. I always thought I had a crap fishfinder or that I am just no good at getting the guys on the fish! (This may still be true however!!!!)
I know that a transducer emits a ultrasonic wave in a cone shape but lets narrow this down to a single line. Because the offset here will in my opinion have the same effect on a cone as on a straight line except the cone will suffer less from it.
Say I am searching for a reef in 15m of water, with an offset of 15deg on my transducer I will miss this reef with 4m. Fair enough.
Now in 40m of water this figure becomes 10m. This is now only for the one component of which my finder was offset.
I am also not taking into account the fact that it was mounted too high which meant I could never read the bottom while planing. The boat therefore was nose high up in the air and this will add even more than 15 deg to that figure. If I now think about what my boat is like just before plain I would say that angle is close to 40. In 40m of water that is 33m!
This is only be how much I will miss my target. I also don't take into consideration how much power/coverage I will lose from not having my transducer sounding straight down and receiving the signal straight up!
What do you guys think? Does this make sense or am I just talking nonsense?
The blue line is the depth line, the green line is the actual direction of the ultrasonic wave. The red line is the distance by which it misses the depth line at a certain depth.
