The Sonar Potion is a buff potion which grants the Sonarbuff when consumed. When fishing while under the effects of the potion, the name of what will be caught will appear above the lure when it is bitten. This lasts for 8 minutes, but can be canceled at any time by right-clicking the icon (), by selecting the icon and canceling it in the equipment menu (), by double-tapping the buff icon (), or by canceling the buff from the buffs screen ().
This potion is especially useful, allowing the player to not waste bait on unnecessary fish as the cast can be left in the water until another fish bites at the line. This can be useful for angler quests as well as crate fishing. It also makes it so the player cannot get trash items even if they reel them in.