The key to consistently successful fishing is attention to detail.
With blackmouth fishing, two of the most important details are:
1. Location/depth of baitfish
2. Size of presentation i.e. "matching the hatch"
The Tomic "tubby" is a 4" plug with a 5" plug cross-section. In other words, by using the tubby you're attempting to represent a shorter bait size -which is predominent in winter- while still enjoying good action on the plug.
The 2.5-3 knot speed range is right on the money and if you're having trouble maintaining a close relationship with the bottom at that speed, I would suggest going to a 15lb Cannon ball.
I used to think that 10lbs was a practical minimum for saltwater salmon fishing.
Now, I rarely fish anything lighter than a 12 and more often than not, I'm running 15 lb Cannon balls and I also carry and run 20 pound balls
When in doubt... Get the big lead out!!!