A top pocket cast net (a.k.a. prawn net or prawning net) is designed to catch prawns. The advantage of this design is the ease of use: prawns gather in the top pocket, which can be easily emptied into a bucket.
Not all top cast nets are created equal: on Australian market only Winged Fish® top pocket cast nets offer absolutely best spread, double knotted mesh and 0.9-1.1 lb/ft galvanised steel chain for very fast sinking.
Buy your new top pocket cast net now, and you'll be best prepared when prawns arrive.