As the name implies, a landing net is meant as an aid to help an angler "land" the fish, or scoop it out of the water as it approaches the angler. These are essentially bags of netting attached to a loop with a handle. Landing nets vary considerably with the type of fish pursued. A big catfish or bass requires a heavier mesh, but not the mesh with the tiny spaces that someone landing small stream trout might want. The loop of the net (the solid opening where the net is attached) must also be suitably sized to match the target fish. Finally, there is the question of what the net's mesh is made of. Rubber mesh is best for catch-and-release fishermen, since it spares the fish injury once it is in the net. Knotted nylon nets, on the other hand, damage scales, fins and gills, so these nets should be used only if the angler wants to harvest the fish.
Sometimes also called "baitwell nets," these superficially resemble landing nets, but their purpose is markedly different. A landing net is a tool for bringing a fish aboard a boat or finalizing the catch of a fly-fisherman standing in a river. Dip nets are for taking fish out of a holding tank, pool or bucket, sparing the angler the inconvenience of getting wet. The mesh netting is rarely as sturdy as that of a landing net, since dip nets are mostly used for fetching live bait and are always used under more controlled conditions than a landing net.
Cast nets are disks of mesh, lined with weights and attached to a throw line. These nets are cast into the water, hopefully atop a school of fish. As with landing nets, the mesh size and material varies with the targeted fish. Cast nets are used mostly for catching bait fish; however, so the size of the mesh will usually not be as varied as would be the case for a landing net. The size of both the radius of the cast net and its mesh are often regulated by state law, and in some states cast nets are excluded from certain areas or outright banned. Always check the local fishing regulations before employing a cast net.
Seine nets are similar to cast nets in basic design, as they too are usually nets with a fine mesh meant to catch bait fish. The difference is in how seine nets are employed. Seine nets are spaced between two poles, with floats at the top and weights at the bottom of the net. The netting is then moved upriver and against the current, trapping fish. Like casting nets, seine net use might be tightly regulated or even prohibited by state law, so always check local fishing regulations before using this type of netting.