About 20 years ago I found a peculiar narrow bit of thin ice that stuck about 100 feet out into Shelburne Pond in Vermont. I have looked for this a repeat of this ever since. I got the following from Doug Merrill on January 29.
I headed over to Shelburne Pond this afternoon to check the ice and get in a quick skate with my wife and son. Access onto the ice requires ginger steps for the 1st 3', but once on it the plate was solid. A group of 3 fisherman was heading out as we were clipping our skates on. They relayed that a group that just left the ice reported 6"-8" of thickness.
Just as we were getting our skates on we heard a commotion and looked to see one of the party had fallen through. Moments later, another one of them fell through as well. The third person, who was trailing the other two, stopped and pushed his plastic tote-sled toward the hole for his partners (turned out to be his brother and his father) to grab. I pulled of my pack, got my throw rope, and started toward them, but they were both out of the ice, lying on it scootching toward the launch before I was needed.
The men were surprised and cold, but able to stand and walk off the ice once they felt it was solid. They were only about 300' from the launch access, directly North of it. It appeared that the rock bluffs may have warmed in the sun and weakened the ice near them.
I tested the ice and found I could not poke through with 4-6 stabs, it was at least 3" thick. I found a couple of recently frozen over fishing holes and found the ice thickness to be 4-6". The surface was a 5-6 grade. My wife was spooked by the fishermen's plunge and decided to hike the nearby woods trail. My son and I skated the Southern end of the lake for 20 minutes or so.
When we left the fisherman had changed and were still by their trucks warming up. I asked if they had ice claws. They did not, but admitted that they'd be a good idea. Fortunately, they will live to fish another day.
If you decide to skate Shelburne Pond, turn East (to your right) once you get onto the ice. Do not proceed due North from the launch. Give the rocks on the Western Shore at least 300' of space. As always, proceed with caution