So I'm new to trolling for silvers in the big river. I will be down in the Longview area, and the mouth of the cowlitz. I've got downriggers and am eager to try for some coho this year. My idea is to run a flasher with 12-18 inch leader with a spinner following. Does this sound good? Also I have some bigger rapalas, crippled herring and flatfish. What depth should I start, 20'? Any advice welcome, thanks!