ReelKnotty:-
spoontrolling speeds are just a generalisation at best.
I've had lots of hits when on side of the boat, when the tackle was hanging dead in the water pretty much while I was playing a fish on the other side. The boat be moving maybe 1/2 a mile per hour right then.
Just try different speeds.
One time I was trolling spoons at around 5mph just for the hell of it.......(it was Coho season....spoons by themselves , no flashers) ).......I was amazed how many Chinooks hit the spoons doing that.
Also had Chinooks hit on "Gun and Run"........that is, stop dead in the water---let the tackle settle....then throttle up quickly to troll speed.
Also had Chinooks hit when I just put the tackle in the water, lowered the downrigger to depth (boat moving but slow) and was just about to start getting up to troll speed.
Then there's "turns"......you troll in a straight line for awhile...and you get zilch......so you decide to do a turn left or tight....and "fish on"........
Also......you are trolling along with,say, the downrigger/lure at 180feet deep.......you decide to bring it up to 160ft...while it's doing that..."bango" fish on......
Sometimes you get hits while lowering the downrigger/lure to depth.
You just never know.........
If a lure doesn't work for me after half an hour in the water, I change the game up (lure depth, location) until something does work.
If it's working I leave everything alone (flasher lure , depth, everything).