Under-ice behaviour lab
Instead of guessing where the fish will bite today, we log depth, pressure, time of day, lure type and real bite reactions for each hole we drill. The result is a living lab notebook for under-ice moves, not another lucky story from the lake.
This home page is your console: one place to see how different holes behave, which setups keep biting when the pressure drops, and why some patches of ice stay “dead” even when sonar looks promising. Every data track below comes from real sessions on frozen water, anonymised but not polished.
Depth & pressure field
The same lake can feel like three separate worlds once you mix depth and air pressure. In PolarHole Lab we tag every drilled spot by its depth band and barometer trend, then track how the bite responds in each zone instead of blaming “bad weather” in general.
Under two metres the light is still strong and the bottom often carries weed. We see fast, nervous bites here when pressure rises after a storm, especially from roach and perch. This shelf looks “simple”, yet tiny changes in sky cover switch it on and off like a lamp.
Between two and five metres rigs often hang just above the break line. This band reacts best to slow spoons and subtle plastics; heavy jigging scares more fish away than it calls in. Here we follow micro shifts in pressure more than any other range.
Deeper than five metres the water becomes quieter but more binary. Some sessions stay flat for hours and then explode in a short window. When the barometer falls slowly, this deep band often keeps biting after the shallows have turned into a desert.
Hole passports
Instead of writing “good spot near the reeds”, we issue small passports for each hole. They record coordinates, depth, structure, rigs used and species met during the session. When you read them as a chain, lake memory stops being a myth and becomes a file you can scroll.
Location
43.•• N / 18.•• E, 40 m off the first weed line, snow cover thin, ice 22 cm.
Session notes
First hole of the day. Roach and small perch reacted to tiny metallic spoons after ten minutes of silence. Bite intensity dropped when we switched to heavier jigs.
Location
65.•• N / 14.•• E, just above the sharp drop from 3.5 to 6.2 m, snow drifted into shallow banks.
Session notes
Pressure falling slowly. Pike followed spoons but committed only during a twenty-minute dusk window. After dark, the passport shows a complete shutdown.
Location
59.•• N / 27.•• E, circular depression at 7.8 m with a soft mud bottom, surrounded by slightly shallower flats.
Session notes
We rotated three rigs: a glowing spoon, a plain tungsten jig and a live-bait setup. Only the quiet jig produced slow but consistent bites, which the passport stores as a separate rig line.
Rig swap trail
When a hole feels “almost right” we do not leave immediately. We mark a trail of rig swaps on a simple time line to see how fish react to spoons, jigs and live bait in that very column of water. The trail below shows one such controlled experiment.
First ten minutes we work a bright spoon with sharp lifts. The sonar shows fish passing but very few actual hits. The trail marks this as the baseline state.
After the first spoon run we clip on a small tungsten jig and slow everything down. Bites appear within three drops, but the fish remain small and cautious.
Finally we send down a live-bait rig at the same depth where the jig was getting weak taps. The bites turn slower but far more decisive. On the trail, this third node becomes the moment where the experiment pays off.
The glowing node on the trail marks the rig that currently performs best in similar hole profiles. As more experiments arrive, the highlight shifts automatically.
Bite timing
We log every hit against local time. The result is a ring of three halos that rarely overlap: short dawn spikes, long quiet days and narrow dusk bands.
Ice noise
Every experiment session receives a simple noise tag. Three lanes below show how bites shift when the ice is silent, creaking or loudly cracking.
Anomaly log
When a hole breaks the pattern, we flag it here with a tiny snapshot and one sentence.
Normally deep pockets peak near dusk; this one woke up at full midday light.
Shelf perch kept biting gently even after loud ice cracks ran through the bay.
Session matrix
We sometimes drill a tight triangle of holes and log them as a single matrix. Depth, pressure and rig choices sit in clear rows, so patterns appear faster than in scattered notes.
Under-ice slice
Before we choose a rig, we sketch a quick vertical slice: ice, depth bands and bottom shape. It keeps us honest about where the lure actually travels.
Each rig gets one target band instead of wandering through the whole column.
Soft mud, clean sand or weed clumps are drawn as simple textures, not poetic lines.
The sketch is updated when sonar arcs disagree with our first guess.
Field loop
The loop is simple: plan, drill and debrief. Repeating it keeps the lab feeling calm instead of chaotic.
Pick two or three clear questions before leaving home.
Drill only the holes you can describe later without guessing.
Note what surprised you instead of only counting fish.
Species ladder
When we stack hole logs by species, a simple ladder appears: some fish accept noisy moves first, others only follow once the water calms down.
Micro decisions
We keep a thin strip in the notebook for small but important decisions: when we moved one metre, changed jig colour or raised the lure just a palm higher.
Slid hole position three steps toward the weed shadow.
Swapped silver jig for dull copper after two missed hits.
Lifted lure half a metre above marks instead of chasing them down.
Doubled pause length when ice noises increased.
Starter layout
You do not need lab shelves to begin. One small box, a notebook and a calm pace already turn every trip into an experiment.
Archive shelf
Each season gets its own row: early ice, deep winter and thaw. We slide hole passports and session cards into these rows so last year’s notes stay easy to reach.
Thin, clear ice and short walks. Bite logs here are full of experiments with light rigs.
Thick snow cover and longer drills. Most pressure curves come from this dense middle band.
Last, softer ice and ringing cracks. We save a separate row for these fragile but productive days.
Quiet invite
You can borrow any idea from PolarHole Lab: hole passports, rig trails or small decision strips. Keep what fits and ignore the rest—the lake will still tell you if it likes the changes.
