Angler Earring

The boost is flat, not a percentage, so it does the most work early when your rod and bait are both mediocre. Later on it is a smaller slice of a much larger total, but it never stops counting. It adds on top of the bonus from either tackle bag rather than overlapping with it, so the Lavaproof Tackle Bag and the Angler Tackle Bag can both sit beside it on a dedicated fishing loadout with none of the three going to waste.

Quest rewards are the only source, and the game refuses to hand you a second copy while one is sitting in your inventory, a portable bag or a saved loadout. That protection flips once you own every fishing and info reward he can give: with the collection complete the block lifts and spares start showing up, which is how people stock copies for a second character.

A spare is never dead weight either. Shimmer cycles it into the other fishing accessories, so an extra earring can become a Tackle Box or a High Test Fishing Line if that is the piece you are missing.