Angler Hat

Nothing here is crafted or dropped. The Angler hands the pieces over as quest rewards once you have logged enough of them, hat first and trousers last, so the set assembles itself as long as you keep turning quests in. No luck is involved, only patience, and since he only offers one job per day the whole thing takes a while to finish.

Two effects that work on the same problem. The fishing power boost improves what comes out of the water, and the set bonus suppresses spawns around you, which is the difference between a quiet hour on a lake and being interrupted every half minute by something that wants to knock you off the shore. Do not wear it for anything else. The protection is token and a real fight in it will go badly. Building your fishing spot inside town stacks with the bonus, since a crowd of NPCs already pushes spawn rates down on its own.

Captain Hat, Captain Vest and Captain Pants count as the same set for the bonus, so you can swap in one upgraded piece at a time and never lose the spawn reduction while you do it. What changes on the way up is how much punishment you can take, not how well you fish.