Well heres some information for everybody.
We went out to Shell island yesterday. Drilled holes and never saw anything less than 18" of ice. About 10" average snow depth with drifts up to 20", some hard packed drifts. No ridges that we saw or had to contend with.
Made it out to the western point of the island by 8:00, setup on the top of the point in 18fow below the ice. Saw 3 walleye and 1 pike from 8-11. No biters. Bottom was soft, no rocks or other structure.
Moved up on the island, still on the western side, to a thinner spot and drilled out a spearhole. Wasn't expecting much for spearing but thought it would be fun to try to sight fish if we could see some walleyes. Ended up on top of the thin ridge in 11fow. Could barely make out the bottom, water was dark even with the sun shining. Saw 1 pike about 8-10lbs and 1 walleye that we figured was around 22-24". Couldn't get either of them to bite. Bottom was soft and sandy, with just a couple small rocks.
Moved back to the west onto a deeper point, 33-35fow that dropped off into the river channel. Drilled a bunch of holes to pinpoint the very tip of the point and setup there. Surrounded ourselves with tip ups from 40fow to 33fow. Saw a couple walleyes on the camera, was able to get 2 up the hole and both got off. Pretty slow until 5:15. Then the perch moved in, just one at a time, ended up with 4 decent perch. After the perch there was a little slow time and then the little walleyes moved in, we caught 4, 8-10" walleyes from then til dark, and that was it. Bottom there was soft without any rocks or anything.
All in all kind of disappointing. Beautiful day without any wind, sun was shining, actually felt really good. We were the only ones out there, could see some permies closer to the pouch area, but nothing anywhere else. There were fish out there, but just couldn't get much to bite. Tried most everything in the tackle box. I think next time we will try up shallower, closer to the island for the last 2-3 hours of light in the evening.
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FWIW, right now the navionics phone app is about shows the water to be about 5-7ft deeper than it actually is.