Crankbait trolling speed vs depth

bkwapisz

Chief Petty Officer
Joined
Oct 20, 2009
Messages
441
I just ordered a little booklet from Rapala that may answer this, but I was wondering how to calculate how deep my crankbait lures will go at a given speed and line length.

I just want to avoid running them into the bottom next year and really have no idea what I'm doing. Thanks in advance for any pearls.

Brian.
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Crankbait trolling speed vs depth

I haven't trolled crankbaits in a while, but wouldn't do so strickly based on depth calculation. It depends on crankbait, speed, line out, current, line diameter, and type of line. Most mfgs depth ratings are just a guide, and in my experience, on the optimistic side.

Unlike the type of fishing you are doing, I prefer to be just tapping bottom. But, if you know the depth where you are just barely hitting, you know how they running with all the varibles. Using that will be much more accurate.
 

bkwapisz

Chief Petty Officer
Joined
Oct 20, 2009
Messages
441
Re: Crankbait trolling speed vs depth

I haven't trolled crankbaits in a while, but wouldn't do so strickly based on depth calculation. It depends on crankbait, speed, line out, current, line diameter, and type of line. Most mfgs depth ratings are just a guide, and in my experience, on the optimistic side.

Unlike the type of fishing you are doing, I prefer to be just tapping bottom. But, if you know the depth where you are just barely hitting, you know how they running with all the varibles. Using that will be much more accurate.


That's another problem I have. Most of my crankbaits have no boxes so I don't know what their running depth is. :confused: Mayb eI should just use something else? Normally for the very small amount of trolling I have done I've used crawler harnesses.
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Crankbait trolling speed vs depth

In very general terms, the longer and wider the bill, the deeper it will go. Testing and recording what depth they hit, at what speed, etc, is what you want to know. What depth are you trying to run them at? Going for suspended fish?
 

bkwapisz

Chief Petty Officer
Joined
Oct 20, 2009
Messages
441
Re: Crankbait trolling speed vs depth

In very general terms, the longer and wider the bill, the deeper it will go. Testing and recording what depth they hit, at what speed, etc, is what you want to know. What depth are you trying to run them at? Going for suspended fish?


Yes, the lake I will be fishing has an abrupt dropoff along one side that goes from 8ft to about 25-30ft rather quickly. I've often marked fish in the mid range there all season. Not sure if they're crappie or what, but we're intending on trying to land some Walleye. I did some very slow trolling a few seasons there and almost landed me a beautiful Walleye. Got him up to the boat, he looked at me, made a right and tookoff with my rig. :mad: That's when I learned that 15 yr old monofilament should be changed... :redface:

Anyway, the plan is to use a planer board or two and troll the dropoff area about 15-20' down, which is about where I saw them. I do plan on using my new boat which has a MUCH better graph than the old one, so I should be able to get on them at least to try to wrangle them in. I have used downriggers once (and the new boat came with the full setup) but this was in 200' of water for lake trout, about 155' down. Personally I think it might be overgunning it where I fish, but again, I'm a newb... :)
 

gonefishie

Commander
Joined
Jul 28, 2004
Messages
2,624
Re: Crankbait trolling speed vs depth

If you know what the bait model is you can find out from the manf. or places like basspro.com, etc...what's the running depth is. This running depth is normally based on 10lbs test line and 20-30 yards cast. Meaning if you use 10lbs line and casted it at least 20 yds out, it will reach max depth during the retrieve. Doesn't that Rapala book lists the different type of crankbait and their depth trajectory based on different line tests?
 

bkwapisz

Chief Petty Officer
Joined
Oct 20, 2009
Messages
441
Re: Crankbait trolling speed vs depth

If you know what the bait model is you can find out from the manf. or places like basspro.com, etc...what's the running depth is. This running depth is normally based on 10lbs test line and 20-30 yards cast. Meaning if you use 10lbs line and casted it at least 20 yds out, it will reach max depth during the retrieve. Doesn't that Rapala book lists the different type of crankbait and their depth trajectory based on different line tests?


Probably, but it's still in the mail... :( Maybe it'll be here next week.
 

wifesbitch

Recruit
Joined
Nov 14, 2009
Messages
4
Re: Crankbait trolling speed vs depth

I just ordered a little booklet from Rapala that may answer this, but I was wondering how to calculate how deep my crankbait lures will go at a given speed and line length.

I just want to avoid running them into the bottom next year and really have no idea what I'm doing. Thanks in advance for any pearls.

Brian.

If you got a few bucks try dipsey divers and floating crank baits. Luhr jensen has a pretty good chart for depth vs. line out etc.
 

Mark_VTfisherman

Lieutenant
Joined
Nov 29, 2008
Messages
1,486
Re: Crankbait trolling speed vs depth

With a little practice in use, the little big jon diver disks and bigger dipseys are fairly easy to get use to to estimate running depth.

You don't have to memorize trigonometry charts but when you know the amount of line out, and can see your line is running about 40-45 degrees, I just compare it in my mind to a rafter and I can figure pretty good with a guess what the "rise" is - that's the running depth of the Diver Disk. I "guess" on the short side figuring that I need to be at or probably prefer to be slightly above the depth I am marking fish.

Running the little Big Jon Diver Disks one day last summer on Champlain was the only way I could get down and away from the boat with 5 of us fishing that day. I turned the weight to the side, and was running my desired 17-20' down and about 35' off the side of the boat. I caught a salmon on that when the guys on the downriggers weren't. I caught one on my lead core too, but I had a long rod off the side so I didn't get into the flatlines or dowrigger lines. Was using a couple of Rapala size 9 for a while, but also used stinger-style spoons but apparently spoons were not in the menu mix that day.

There is a book called "Precision Trolling" which contains running depths for a ton of setups. I might suggest picking up that, but I think you would be better to buy a good sonar first.
 

bkwapisz

Chief Petty Officer
Joined
Oct 20, 2009
Messages
441
Re: Crankbait trolling speed vs depth

With a little practice in use, the little big jon diver disks and bigger dipseys are fairly easy to get use to to estimate running depth.

You don't have to memorize trigonometry charts but when you know the amount of line out, and can see your line is running about 40-45 degrees, I just compare it in my mind to a rafter and I can figure pretty good with a guess what the "rise" is - that's the running depth of the Diver Disk. I "guess" on the short side figuring that I need to be at or probably prefer to be slightly above the depth I am marking fish.

Running the little Big Jon Diver Disks one day last summer on Champlain was the only way I could get down and away from the boat with 5 of us fishing that day. I turned the weight to the side, and was running my desired 17-20' down and about 35' off the side of the boat. I caught a salmon on that when the guys on the downriggers weren't. I caught one on my lead core too, but I had a long rod off the side so I didn't get into the flatlines or dowrigger lines. Was using a couple of Rapala size 9 for a while, but also used stinger-style spoons but apparently spoons were not in the menu mix that day.

There is a book called "Precision Trolling" which contains running depths for a ton of setups. I might suggest picking up that, but I think you would be better to buy a good sonar first.


Great info, thank you! The boat has 2 Lowrance sonars and I do know how to read those, so I guess I'll just have to learn to read the angles of the lines like you suggested. I might look into that book as well. Hey thanks again!

Brian.
 
Top