In the process of fishing the bottom, the general situation is that the bait into the water, the lead pendant suspension, the weight of the accessories below the drift and the buoyancy of the drift play a role of mutual checks and balances. The drift will also remain at a fairly balanced eye level when the hook is in the water. When a carp eats the bait, usually the fish will choose to observe around the bait first, to make sure there is no danger, and then try to bite the bait, and will eat it only after it feels palatable.

Fish inhaling the bait will directly lead to an imbalance in the relationship between the drift and the fittings, and the bite will suddenly increase the weight of the fittings, and the drift will appear to be a strong beat. The magnitude of the drift depends on the suction and weight of the fish and the sensitivity of the line, as well as the depth of the water.

Top Mouth

Top Mouth(1)

Top Mouth occurs most of the time when the fish is floating or when it is off the bottom (and occasionally when it is on the bottom). When floating, the line is most likely to be at its most sensitive, all things considered: the bait can't be stationary on the bottom, it will move slightly with the waves. The fish sees the bait suspended in the water and comes over to eat it, but this time of eating is different from when fishing on the bottom.

Because most of the food that the fish eat in the water will move around in the water, the fish instinctively think that the bait will also move, so they reduce or omit the observation around the bait, and more often swim to the bait's position, and then inhale the bait into their mouths. Because the fish is moving toward the bait, the speed at which the fish sucks in the bait and the speed at which the fish is moving cancel each other out, creating a subtle stutter.

It's hard to notice without looking closely. But if the two cancel each other out, the drift should stay still by definition, and a top lip would be impossible. But in reality, the situation is completely different, and the reason for the drift is that it has a lot to do with the direction of the fish's movement.