Fished in Beaucedine Glacier at any of the ponds. Fished them today near the Outpost with Halcyon and Sabiki Rig. This fish caps at 49 Fishing. I've got Lv43 Fishing and i still got the lack of skill messages.
Skills for catching vary a little when using a rig and are trying to catch varying amounts of them.
49 Single Icefish
52 Two Icefish
54 Three Icefish
While having level 50 fishing, I can't seem to catch more than just the single icefish reliably, this while wearing the fishing gear. When my skill was 48 I was really only able to catch the single icefish somewhat randomly.
So it seems like you need your base skill leveled to the appropriate point to be able to catch these with a rig reliably.
