Downrigger Backlash

[Just1skipper2]

Hello folks, I would appreciate information on

downrigger backlash. For instance, how to reduce it, what is normal, if I have say 45° lash where is ball depth and what should I do if lash takes ball trace off the sonar. Should the sonar always see ball and stacked lines ?

Thank you for supporting me. 

[VooDoo]

I think you are referring to blowback.  There are too many variables to give you definite answers.  The lighter the weights, the more blowback.  The deeper you send them, the more blowback.  Speed, current, etc are all factors.  

[Just1skipper2]

Yes I'm sorry. I meant blowback and losing image from sonar

[ifishy]

It's not necessary to see them on your sonar but the more blow back the more they are in the way of other lines and netting its really about comfort 

[VooDoo]

Heavier weights have less blowback.  U can also tilt the back of your tranducer up a little, but this may make your depth reading off slightly.  I run a Lowrance carbon and humminbird helix with the ducer tipped up a little. The helix picks up weights a little better.  There is about a 2' difference in depth between the two.  

 

[chinook35]

This topic has been addressed many times on this forum. There are charts that can show the approximate depth of your weight using math , amount of cable out and the angle of blowback  using your sonar ( distance finder ) to track your weights does NOT show you the true depth of your weight  , only the distance of the weight from the transducer  if you have 100 ft of cable out and you have  20° of blowback , your weight (and lure ) are actually running at about 80 ft   Your sonar may show that you are fishing at 100 ft , but it’s actually showing the distance from the ducer , not the true depth  takes a while to get your head around this but it’s true. All geometry 

 

[chinook35]

There is rather more than a 2’ difference between the amount of DR cable out and actual depth of your weight    blowback ( and the actual depth of your lures) is depending on speed , currents , and the weight of your weight (pun intended)   my probe shows actual depth of my presentation. There are times I’ve had to let out 150 ‘of cable to reach 100 ft down   Watch the angle of your cable the more the angle , the more cable you have to let out to reach the desired depth. Don’t rely on your sonar to tell you how deep you’re fishing  it can only tell you how far your weight is from the ducer , not how deep it is 

 

[VooDoo]

I was referring to the difference between what the humminbird transducer and lowrance transducer showed for bottom depth because I have the back of the humminbird ducer tilted up a little.  I can see the rigger weights better but also can see bottom depth on plane better.  I understand blowback and realize that what sonar shows is not actual depth of ball.  I do know that if the ball doesn't show on sonar I have to let a signicant amount more cable out

 

[Sk8man]

An additional variable is the particular capability specs of the transducer. For example if you have  Lowrance with a combination 83/200 khz transducer the weight may go fairly quickly out of the cone if set for 200 khz versus 83 khz because the cone angle capability is narrower. If you have a combination transducer set the transducer to the lowest number and see what it does. As mentioned all those other factors also come into play.

[VooDoo]

That's true with the cone angles.  With the humminbird ducer tilted up a little it points back a little further.. thus showing the weights better.  But it doesn't show how far the weight is from the back of the boat.

if I really want to see how far the ball is behind the boat I can point the lowrance active target transducer to the rear.  This will show exactly where the ball is and show depth as well, although I'm not sure how accurate the depth reading is.  It does show quite shallower than the 2d sonar shows.     But I have to subtract the length of the boat since that transducer is in the bow.  

[LongLine]

Stuff already mentioned does affect blowback however there are a couple other variables.  (!) size of your cable.  200 Lb has much more blowback than 150Lb wire. (2) coated cable has more blowback than uncoated (3) shape of your weight.  Cannonballs have more blowback than torpedo or fish shaped weights. (4) hardware you're running.  Probes will require at least 2 Lbs more to achieve the depth you want.  Flashers & pinchpads will have a slight effect also. 

 

 

[sherman brown]

another big factor is not only the weight but the type of weight you use. I have used 12# and 13# pancake weights for a few years. but last summer we used 8# dredge weights and had less blowback than with the pancake weights. then I found a guy who sells the dredge weights at a great price. so I bought 10# weights last fall to try this summer. if anyone wants his info just pm me and I'll gladly give you his website.