I usually run below the suggested numbers. For big kings, I like .530 and big silvers I run 600-645. This could be my boat. I run a 20' Trophy. I have the quick disconnects in the Scotty BBox line. Keep plenty of corrosion resistant oil on these and keep your battery terminals clean. Corrosion in these wires can do funny things. I keep a digital voltmeter on board. The .530 yielded a 40#+ king at westport this year. The lower numbers also seem to increase the size of blackmouth too. The begining of the year in the south sound I was not getting any fish. At the end of the day I checked the voltage. It had jumped to .9. Unplugged the BB wires and got fish on. I had the wiring go bad under the boat. Replaced the wiring and was back in business