28 ounce Mojo..depth and amount of line??

[Spot77]

Like the title says.....I want to run this one deep obviously...like 50 to 60 feet. A lot of lures come packaged with good estimates of depth = weight+ length of line but not this one.

So would 150' out get me to where I want to be?


Also, does anyone have a generic chart they can post that shows the formulas I'm looking for?

I know I sound like a broken record, but most of my fishing has been freshwater and pretty shallow saltwater. So getting into this deep water trolling thing is pretty knew to me.

Thanks y'all.

[garlien]

These should help...

http://www.striperfishingtackle.com/..._indicator.htm

[Skip]

The depth charts are OK but only real way to know how deep your lures are with your line off your boat is to take time and do an old school tactic.

It's simple and only takes about an hour.

You'll need a line counter and pencil / paper and 1-2 crew members.

Start with the deepest combo you plan to run and set it in deep water. Let it out the distance you want - then at trolling speed , go into shallower water until lure bounces. Record the line length and depth it touched.

Repeat with other combos until your entire spread is mapped out.

One tip- once about 150 feet of line is out - lures tend to start riding higher.

Even then - there will be slight variance if a rough day ( boat speed tends to go fast /slow on swells ). Going into current vs with it can alter depth as well.

Once you get your chart done - compare it to the published ones , fair bet a lot different.

Other trick - watch your depth finder and when you spot a fish at say 30 feet and it hits 10-20 seconds later , safe to assume that rig was around 26 to 29 feet.

[Spot77]

Thanks Skip. Looks like we'll have time to work up a few good lengths today and Mike said he knows his Penns well enough to have a good estimate on the amount of line set out.

I did not know that about the 150' rising lure thing, but I guess that makes sense with the amount of pressure on the line pushing it backwards along with the angle of the line.

Wish us luck today fellas....I know at least one other CBA'er will be within VHF distance and maybe even binocular sight of us today.

[Southerly]

i think the fishing line shape is kind of like diagram below. (turned 90* vertical, the lines below would represent a supple rope or chain hanging under its own weight, ie constant weight/unit length. http://en.wikipedia.org/wiki/Catenary )

but as shown below, the lines would represent fishing line being pushed back by water resistance, but held down by the weight of a lure (that has no resistance itself). i don't think this is a completely accurate model of trolling situation because the water resistance on the line is probably not constant/unit length, but is probably determined at least partially by its angle to the flow.

for horizontal force varies by angle - see the wiki non-uniform chain derivation. i think you would just need to substitute an equation for water resistance of the line as a function of its angle for 'w', then solve for rho.

in any case, i think there is a line length where there's sum total enough water resistance on the line that the lure won't go any lower. instead, any additional line is basically going straight out along the water.

but given the choice between charts, equations, guessing - i would just do whatever Skip says,...

[Spot77]

Experience won.

we were able to put that thing right on the 45' mark doing basically exactly what Skip said. We watched the Lowarance and the rod....when the rod showed the lure councing off the bottom and the Lowrance showed us in 45 to 50' consistently we reeled up a little until it stopped bouncing.

That's Chesapeake Science 101 right there.

[Southerly]

a friend told me he picked up a 44"r (with pics) near HI bouy this friday using 32oz! on white shad 12"!! umbrella!!! (reported to be out 80')

i had to comment that it must have been helluva thing to reel in. he said it wasn't as bad as a 26" he had that ran from side of spread to the other.

dam fish stories,...

[Skip]

Glad to hear it made sense to you and you got a few fish.

Perhaps one day a formula will be worked out to determine lure depth but until then - old school tricks still work.

It can get tricky in the bay due to the different density of water.

Water at 38* is the most dense - learned this from a speed boat racer.
He carried 5-6 props -each to match how dense or thin the water was.
They needed every mile an hour they could get and told me there could be as much as 2-3 MPH difference on a prop when water was warm ( 80* ) vs cold ( 40* ).

Same thing sorta comes into play with lure depth. Other factor - some times we get two different direction currents in the bay.

Upper water to say 25 feet might be outgoing - then below that can be incoming. This can cause an S in the line.

Seen chum baits flow behind the boat to a point - then start coming back once it sinks into opposing current.