You will need less power the more shallow the water you are fishing in. For every 100 watts of power you’ll be able to see 400 feet, with a rating of 50 kHz. With 200 kHz, though, you’ll see 100 feet for every 100 watts of power. A good fish finder will let you split it up, though, and with split frequencies you can dial in the perfect amount for what you are needing at the moment.
The type of power and the wattage will be an important part of your fish finder if you need the most powerful option possible. The minimum that you should be looking at will be about 600 watts, although there are options up to 3,000 that are recommended for serious fishermen.
The Elite-7 Ti from Lowrance is a combination touchscreen fishfinder/chartplotter with powerful performance matched with high-end features and functionality at an affordable price. The 7-inch high-resolution, LED-backlit touchscreen provides quick access to all its features. High-performance sonar provides views of the environment underneath your boat. Balanced sonar needs are covered by simultaneous Low/Mid/High CHIRP or alternatively, StructureScan HD while offering 83/200/455/800 kHz frequency coverage.
The all-new, rugged Garmin STRIKER 4 DV fish finder series has a highly sensitive GPS that is created to let you indicate your favorite fishing spots, so that you can find it easily the next day. It also has the CHIRP traditional sonar that displays sharp fish arches along with perfect target separation.