New River, Squirrel likes at least 8-pound test, and he prefers 10.
I should have known better, having fished that section of river several times. Sometimes I forget, though. I quite commonly target stream smallmouths with 4- or 6-pound-test and pretty light rods, but the New is a large, crashing mountain river, which calls for making longer casts and and contending with quite a bit of current. It also lends itself to bigger lures than I often throw for stream smallies, so heavier line and stiffer rod are more effective for making good presentations. The New is also loaded with abrasive rocks, and it holds some giant smallmouths, which will break your heart if they end up breaking your line.
I don't know that I lost any heavyweights on my most recent trip. I don't know that I didn't, either, though, because I broke my line on a few hooksets and failed to hook quite a few fish that I never saw or felt enough to sense their size. I do know that I missed an inordinate number of solid strikes from fish of all sizes.
The major shortfall of my light tackle was that I didn't get good enough hook penetration and missed far too many fish, either by not them at all or by them shaking off partway through the fight. Between rods that were too soft and a drag that I had to keep a little loose because of my light line, my hooksets simply weren't as effective as they should have been. I also didn't end up using the ultralight much because it was just too light, so it was hard for me to keep complementary lures rigged and ready and to fish spots all the ways I would have liked.
I still caught an enormous number of bass on that particular day because the action so incredible. Had the bite been slower my sub-par hook-up ratio would have been frustrating. I enjoy ultralight fishing as much as anyone, and I'll still carry little stuff when the situation reasonably allows for it. I was reminded, though, to keep in mind that a number of factors (including fish size, river size, cover thickness, lure size and style and hook size) affect the right rod, reel and line size for a day of fishing, and that it's generally better to err heavy than light.
For more information about the tremendous smallmouth fishing on the New River, visit Mountain State Anglers.