definitely run the 83 or 50 mhz instead of the 200 for deep water trolling. i can actually pickup my down rigger balls down to about 120 with my elite 7hdi. Ive only had my unit a month or so, but i have the general use, fastest ping speed, bumped up the scroll speed, and run the noise reduction and surface clarity off. There is a trade off between picking up details and drowning out the noise, you'll have to keep playing with the different settings to try and find the sweet spot for your boat. For instance where your transducer is mounted in relation to your trolling/main motor will effect your settings . u'll have to mess with the surface clarity noise reduction to drown out the motor noise if its too close