Unfortunately a lot of companies fudge their figures to impress the public and sell their product,a 1kw Lowrance/Humminbird is not going to deliver like a 1kw JRC,Koden or Furuno if they did you would see them on commercial boats you can change the transducer but it will not increase the power of your unit it will only add clarity to what you are already receiving,I would want to test one before shelling out cash for one.I use a Furuno 582L a 600wt unit firing through an Airmar P66 transom mount transducer also rated to 600wt,I have no problem at all seeing fish in 300 to 400 metres of water in high freq as well as low freq.