Sounding at Speed

[Black Pig]

Just purchased a new Humminbird 787, and lose the bottom when travelling at speed. Is this normal or is there something I need to fix with the transducer?

[wiz]

Is your boat a tinny?
More than likely your transducer is not deep enough.
Is the transducer parallel or slightly pointing down?
Some pics of your mounted transducer will help the guys on here work out why it is not working at speed.

Cheers

[milligan]

Hi Black pig,
At speed your change the angle of your transducer, it depends how yours is set up.
Cheers Lew

[PADDLES]

have a look at how deep it is too black pig. i've just installed a 727 on my glass boat and fluked it, the thing reads perfectly at any speed but it does sit down in the water a bit. the humminbird instructions ask for it to be right down in the water if you look at their measurements in the instructions. i also angled it slightly forwards too.

[Local_Guy]

lower the thing a little further in the water. one thing i found with the humminbirds they like to be a little lower than normal.

[ffejsmada]

I've got a 777 and the only way to get mine to read at speed was to lower it right down.
I didn't like the depth it sat at to enable it to read at speed as the rooster tail was huge (and you looked like a right ###### as well), also when beaching the boat it could have caused damage to the transducer as well.

I then lifted it up a bit and at speed it would work when i turned to starboard, digging the tranny in deeper.

Stuff it, that's no good.

I've now lifted it up to read at about 6 knots which I find ok as I only fish estuary anyway.

[reidy]

Most likely the transducer is not mounted low enough.When your boat lifts onto the plain the transom dips and then rises.When plaining along the boat is only sitting in very little water at the transom base eg at the rest the transducer is submerged but on the plain the transducer can loose contact with the water due to this lifting effect.
Hope i explained this clearly.
Cheers
Reidy

[BigE]

H/Bird 787 reads at 50kph the only issue i've had is in quada beam at speed the left veiw (motor side ) has some interferance. Not an expert tho I just size it up by eye and slapped it on.

BigE