depending on the hz of the transducer usually the lesser the hz the bigger the cone if i recall.. Depending on your units hz wil depend on where the fish is. But either way.. They are under your boat!!! Most standard units operate on 54hz and 200hz. 54hz has a 30 degree cone downwards from your transducer and 200hz about a 10 degree angle cone. All this info will be in your booklet.