Field Notes / October 2026
Braid vs mono: how your line changes lure depth
At a glance
| braid | thin, zero stretch, deeper |
| mono | thick, stretchy, shallower |
| difference | up to 20-40 % |
| fluoro | +5-15 % vs mono |
Quick answer
Thin line lets a lure dive deeper. Braid is much thinner than mono at the same strength and doesn't stretch, so lures on braid usually run noticeably deeper, by 20-40 % in some estimates [1]. If you switch line and don't adjust, you are fishing a different depth.
The problem
Everybody has an opinion on braid versus mono. Very few anglers have ever seen the actual depth difference with their own lure, at their own speed. Without that, switching line is a gamble on where your lure ends up.
01
Why diameter matters
Water pushes on your line. A thick line has more surface for the water to push, which creates drag and lift that pull the lure up. A thin line slices through and lets the lure's lip do its job. In the Precision Casting study, simply going from 14 lb to 8 lb mono made a crankbait run about 20 % deeper [2]. The same researchers name line diameter and cast distance as the two main factors for diving depth [2].
With PROBE →
PROBE shows the actual running depth on every cast, so the difference between lines stops being a debate. Fish one line, switch, fish the same lure again: the app shows both depth curves.
02
Braid
Braid has a small diameter for its strength and almost no stretch. Less drag means more depth, and no stretch means the force goes straight to the lure's diving lip [1]. The trade-off: braid is visible, so most anglers add a fluorocarbon or mono leader.
03
Mono
Mono is thicker, it floats somewhat and it stretches under load when trolling, all of which make lures run a little shallower [1]. It is forgiving, cheap and great when you want a lure to stay higher.
04
Fluorocarbon
Fluorocarbon sinks and is typically somewhere in between: about 5-15 % deeper than mono depending on diameter and lure, by one calculator's estimate [1].
05
Practical rules
- Switching from mono to braid? Expect the lure to run deeper. Shorten line out or pick a shallower-running lure to stay in the same band.
- Fishing over weed? Thick line can keep a lure just above the tops.
- Want maximum depth without weights? Thin braid and a long cast or long lead.
- Using a dive chart? Check which line it was made with. If yours is different, the numbers are off.
Settle the line debate with numbers.
See how PROBE works →06
Run the test yourself
Here is a simple test that settles it for your gear. Pick one lure, one speed, one line length. Make five passes on braid and five on mono, with PROBE mounted the same distance above the lure each time. Compare the average running depth in the app. Ten minutes, and you have real numbers instead of opinions.
Field log /
Same jerkbait, same cast length, two lines
| Braid 0.13 mm | Average 2.6 m max depth over 5 casts |
| Mono 0.30 mm | Average 1.9 m max depth over 5 casts |
| Difference | 0.7 m, about 35 % |
On braid the lure reached the weed tops; on mono it ran above them. Choose line for the depth you need, not out of habit.
Field rule
Changing line is changing depth. Treat it like changing lures.
FAQ
Frequently asked questions
Does braid make lures run deeper?
Usually yes. Braid is thinner and doesn't stretch, which reduces drag. Some estimates put the difference at 20-40 % compared with mono.
Where does fluorocarbon fit in?
Somewhere in between. By one estimate, lures run about 5-15 % deeper on fluorocarbon than on mono, depending on diameter and lure.
Should I change lure or line when I switch to braid?
Either. If the lure now runs too deep, shorten the line out or pick a shallower-running lure to stay in the same band.
Measure what your line does to your lure. On every cast.
Get PROBE →Sources