1 - 20 of 21 Posts

Joined

·
10,881 Posts

There are 4 variables that would effect the chart and it's accuracy.

Weight of the ball, boat speed, current direction, and ball depth. Any change in any one of these can and does have a noticeable effect in cable angle.

The problem I would see in any chart is just a couple of degrees of cable angle change, compounded by the variables would have a fairly significant impact on actual depth calculations. It is difficult to measure by eye small changes in the cable angle.

Don't your down riggers have depth counters?

You can also get approximate depths by slowing your speed to keep your balls in the depth finder cone angle and they will show up on you graph. However remember that your balls when at most trolling speeds (depending on ball weight, current and speed) will be on the outside of your cone angle and show up as deeper on your graph than they actually are running. The difference will once again depend on the variables. The difference could be a foot or two or more.

Like any line counter reel or depth counter on a down rigger knowing the exact depth is not as important as repeatability. The counters let you reset a lure at a given reading, whether it is 36 ft or 40 ft doesn't really matter as long as it's working and you can return to that same depth or make changes and be able to measure any changes in depth presentation that you make.

Joined

·
2,529 Posts

here is a simple calculator

http://www.1728.com/trig.htm

Joined

·
1,526 Posts

Ball weight, cone angle, trolling speed, deeper on the graph...The only thing I can do is slow my speed! All of the things that come to mind!You can also get approximate depths by slowing your speed to keep your balls in the depth finder cone angle and they will show up on you graph. However remember that your balls when at most trolling speeds (depending on ball weight, current and speed) will be on the outside of your cone angle and show up as deeper on your graph than they actually are running. The difference will once again depend on the variables. The difference could be a foot or two or more.

I was robbed! My balls don't do this ...and talking in terms of a foot or two?? Man...I would be happy with a few inches!

Kim...you must be "DA MAN"!!!!

Joined

·
4,374 Posts

with pea size brains. Repeatability is the key.

If your not catching any fish, vary your depths

a few feet at a time. On my boat I run 2 riggers

at different depths along with dipseys and

jets. Find the program and go from there. If

the fish are that picky I doubt you'll catch many.

Joined

·
947 Posts

Toxic, if you have your keel offset correctly configured, that would be about what was I figuring. 1 foot per ten. looks like maybe that's a little long if you're showing 2 feet at 30, but without the angle of the arc it becomes totally speed dependent.

Thanks for the replies

MIkeC

Joined

·
947 Posts

Roger23 I don't believe that calculator will work because it isn't a right angle anymore; it's a polygon. at least I think it is. so if there's a calculator that you can plug in the arc, the distance down and the hyptenuese to get the fourth leg, ie., the distance from the ball to the base, that'd be the one to use. I think I found it but they were talking about sines and cosines and I was lost right about there.

Thanks, MikeC

Joined

·
4,374 Posts

.

Roger23 I don't believe that calculator will workbecause it isn't a right angle anymore; it's a. at least I think it is. so if there's a calculator that you can plug in the arc, the distance down and thepolygonhyptenueseto get the fourth leg, ie., the distance from the ball to the base, that'd be the one to use. I think I found it but they were talking about sines and cosines and I was lost right about there.

Thanks, MikeC

Man, you know all them big words and you can't figure it out LOL. I feel ignorant now

Joined

·
3,317 Posts

Mike, heres a link for any professional questions you would ever need about downrigger questions. There is a ton of info...you might want to join the site.Does anyone have a chart or a math calculation to show the depth of your cannonball with various degrees of swayback? I've heard of the Osprey Computrac but I can't find it.

Thanks, MikeC

Van

http://www.michigansportsman.com/

Joined

·
2,338 Posts

If you are marking fish on your screen as arcs. The the bottom of the arc is when the fish is on the outermost part of the cone. That is close to the level that you would want to mark you downrigger since its on the outside of the cone angle too. IF in fact you want to fish at the exact level of the fish.

It really dosen't mater that much since its a known fact especially with salminoids that they love to stay down in cold water and dart up into the warmer water to grab their pray. So being above the fish may be better sometimes.

I guess this would matter the most if you are trying to scrape fish off the bottom in deep water. I beleive most salmon charters that do this in water of 60-90 ft routinely use 14lb balls and just bump their cables a couple of feet deeper. I know ive hit bottom in 80 ft with about 87 ft of cable out at speeds around 2.4-2.7 with a twelve lb ball.

Joined

·
3,317 Posts

Joined

·
425 Posts

Also, it is called "blowback".

JD

Joined

·
10,881 Posts

if I've let out 40 feet and the downrigger line's on a 45 degree angle, which is extreme, the ball would be running at 20 feet.

MIkeC

Check your math

Joined

·
15,946 Posts

Joined

·
4,374 Posts

Ahhh.....simplicity at it finest. To much info boggles the mind.

Joined

·
218 Posts

Joined

·
947 Posts

Lundy, I used a six-inch scale for 40 @ 45 degrees and I got 11.66 feet off the bottom. I tried to do it in the yard but my numbers were way off.

Thanks to all who replied.

MikeC

1 - 20 of 21 Posts

Join the discussion

Ohio Game Fishing

A forum community dedicated to Ohio’s fishers and enthusiasts. Come join the discussion about safety, gear, tackle, tips, tricks, reviews, reports, accessories, classifieds, and more!

Full Forum Listing
Recommended Communities

Join now to ask and comment!