Try putting the flasher with a long steel leader on your rigger ball. Then troll with just the Kroc on it and troll fairly fast, I find silvers like it fast vs slow when I troll. I see people troll too slow and they wonder why they are not catching fish. Kings I troll 1.8 - 2.4 mph on GPS, on silvers 2.7 - 3.6 most of the time or faster depending on wind or tide rip. I think boat size matters on your speed as well, but variation is the key...... Troll in s curves and turns vs just going straight all the time. Hope this helps
For the higher speeds I usually run spoons, dodgers always seem to work better than flashers, though the flashers get the nod when I'm down at my usual 1.8-2.2 king speeds. I also run spoons without the dodgers or flashers, but usually on sunny days in the top 30-40' of water when the spoons are easy to see. But overcast or chop or fishing deeper, the hardware goes on the leader.
Interesting enough, the silvers so far this year have been downright weird. Not seeing many jumpers or finners, and not having any luck blind trolling faster up near the surface. Wanted a few more feeder kings for the freezer, so I went to flashers with purple tray herring (plugcut) and searching deeper. Boom. Got right into the silvers. Been limiting out or nearly so every day we go out, and we don't fish that long on any day. Meanwhile guys fishing for silvers in the usual way with the usual gear are whining about so few silvers. Interesting thing, though there are needlefish around we've found some capelin deeper. The silvers (and kings) are on the capelin and ignoring the needlefish. Every fish we've dressed has had a belly full of capelin.
Anywhere from 80 to 160, amazing enough, depending on where the layer of capelin is holding. Easy to spot that layer once you've seen it. Rather than bait balls or heavy layers, it looks like a stripe of "pepper grains" on your screen, and usually pretty well limited to a depth band about 10' thick, whatever depth you find them. I've almost never seen them shallower than 80 from the surface.
We were anchored in 130 for halibut when that scattered layer of pepper grains showed up between 90 and 100. My wife was retrieving a dart jig, hooked a silver as it passed through, but lost it at the surface. There were 4 of us onboard and we all switched to cutplug green tray herring under 1 oz weights.
Things got wild in a hurry. Over the next hour we landed our 8 silvers, as well as three "surprise" kings in the same size range. Had three doubles going, and lost a few too. First time mooching for our friends, and now it's all they can talk about. I asked if they wanted to go trolling today, and they said no way. "Let's mooch!"
You wouldn't know there was a silver anywhere. We only saw one jumper all afternoon, and several guys trolling through the area looking for them up near the surface struck out, complaining about "no silvers" this year.
Back at the landing, all 11 of the salmon were jammed with small capelin around 3" long. Interesting enough, not a one in the halibut.