Read the “jigging for cusk” thread just a couple threads under this one. The quoted comments from the C/O in a post near the end are spot on. As someone else posted, in jigging for them, use a ‘noisy’ and/or glowing presentation tipped with cut bait. Pound the bottom and a few inches up from it. As for spots, you’re on your own. But there are plenty of old threads you can look through that will recommend likely depths and potential structure or bottom content.
