If serious bottom fishing over 200m is your go 1kw is vital I use 1kw transom job on a585 and we can mark blue eye and bass in 600m whilst drifting. clutter is a drama underway on 50 khz but can be minimised with a through hull installation (but may cause problems on a trailerboat)If your fishing under 200m save your money and buy a sexy rod and reel as your looking at 1000-1200 bucks