This is pretty complete list of current models and their stated wattage. It gives a good indication of which sonars can give good deep water penetration and potentially better separation in shallow.
This is only a chart and does not in any way recommend one brand.
This should make you comparison shopping easier.
Make Model Peak wattage Claimed R.M.S. wattage
Vexilar Fl-22 400 50
Vexilar Fl-20 400 50
Vexilar Fl-18 400 50
Vexilar Fl-8 400 50
Marcum Lx-7 4800 600
Marcum Lx-5 2500 300
Marcum Lx-3 2000 250
Marcum Vx-1 1000 100
Marcum/Showdown5.6 8000 1000
Humminbird 55 2400 200
Humminbird 345 2400 200
Humminbird 45 1800 225
Humminbird 35 800 100
Lowrance Elite5 4000 500
Lowrance x67 800 100
