Crabbing is a great way for families to spend a day on the waterfront or on the water. The thing about crab traps is that they are relatively easy and cheap to make, so with some basic equipment and a little know-how you'll be catching crabs to drop in the dinner pot in no time.
Prepare the hoop net. You can buy a hoop net at any fishing store. The nets come in a variety of sizes and perimeters. The hoop net resembles a basketball net with a thinner metal circle running through the net at the top. Unlike a basketball net, it is closed on the bottom. It also has a smaller metal circle at the bottom. If you can't buy a hoop net, it is easy to make one since it just consists of two stainless steel rings and an interwoven nylon net over them. Just remember that the top is open and the bottom is closed.
Cut a strong rope with a sharp knife into three identical pieces. You can use any kind of strong thread such as a clothing line you can buy in almost any home department store. Make each piece at least 1 foot long. Leave enough rope since you will need to lower the crab net into the water. Basically, the length of the rope depends on the depth at which you will be catching crabs.
Tie three ends of the three ropes to one another. Use a strong, firm knot and check to make sure it is secure.
Tie the free ends of the ropes to the perimeter of the hoop net. Note that the three knots have to be evenly distributed along the metal circle perimeter. The result should resemble a very loose peace sign.
Tie a strong, small metal ring to the joint knot at the top of your crab net.
Tie the rest of the rope to the metal ring in the middle of the crab net. Make sure to check the knot so it is secure and firm enough. The length of the rope will determine the depth you set the crab net.
Make sure to obtain any necessary fishing license before you go crabbing. Instead of a clothing line rope, you can try using a common braided nylon cord. If you want to engage in serious fishing and crab catching, learning how to make various knots is always a good idea.