In the past few years a fair number of long rod buffs who fish big waters have tried their hands at 10 to 11 ft two handed rods in 4,3 and even (rarely) 2 wts for trout fishing. I do it myself on the right waters and it is loads of fun and quite productive.

The rods are very light in hand and have limits in terms of managing big fish efficiently -- just like other UL fly fishing.

What is the consensus here on this style of fishing in terms of UL status?

DDB

First of all, it’s really nice to see some activity on this forum again. But please be patient with me while I weigh in on this topic.

When the subjects of UL switch rods and micro-spey casting first came up, I was a bit skeptical. Modern conventional wisdom dictates that a spey/switch rod should take a line that is 2 or 3 weights heavier than what is recommended on the rod. Why would that be? One possibility seemed to be that the rods were under-rated, in which case a 3-weight switch rod that actually takes a 5- or 6-weight line to make it perform shouldn’t be called a UL fly rod. But perhaps there was more to it.
Upon looking into this single-handed spey/switch casting business, I realized that I had done switch casting quite some time ago, but without all the fancy names for different casting moves. So the next step was to try it out.

That involved taking a 7 ½ foot 3-weight to a nearby stream and trying it for switch casting with a 5-weight DT-F line. And it worked quite well, thank you! My understanding is this. When overhead casting, there is an abrupt change of direction (180 degrees) and the standard 30 feet of aerialized line loads the rod at the end of the back-cast and the beginning of the forward cast. But with roll/switch/spey casting with a 7 ½ foot rod, only some 15 feet of line in the D-loop initially changes direction, and only about 90 degrees, but at any rate it is a more gradual transition. So the 3-weight switch rod that takes a 5- or 6-weight line is probably rated correctly.

It still seems debatable whether a 3-weight switch rod that takes a 5- or 6-weight line is really in the realm of ultralight fly-fishing, or whether it is a grey area. But one thing that I aim to try after this winter (in the southern hemisphere) ends is a 3-weight line on a 0- or 1-weight for switch casting. That would unquestionably be UL

I'm still confused on the switch/spey weight ratings, even after purchasing an 11' 5wt "switch" rod. The rod was apparently rated & labeled by someone who was even more confused than me. All I can figure was that it was an 8 weight "switch" rod and they gave it a conventional rating, but subtracted instead of adding 3 weights. It takes an 11 weight conventional line to (overhead) cast it, and an 8 weight switch line does quite well for spey casting.

I would say the UL classification would apply to any rod that overhead casts a 3wt or under line well. The uplining to meet casting variations is just an adaptation to casting methods, and the rod itself is still a UL rod.