You need to be in an area that is thick with sand shrimp, thick enough that the sand is soft with all the holes. If the sand is hard then the pump gun won't work, you have to use a regular clam gun. What you do is stick about 12" of the tube in the sand, pull up on the plunger, lift the tube out to the side of the hole, push the plunger down dropping all the sand and water next to the hole, put the tube back in the hole and repeat. I will usually pump each hole 5-8 times, it ends up sucking the shrimp from the surrounding holes. I usually get 2-6 shrimp per hole. Where I dig I will get 10 dozen shrimp in about 15 minutes.