Attractant is very important for blackfish float fishing. Not only does it attract fish, but by using the current and adjusting the attractant you can make it a lot easier to catch blackfish.
Divide and Conquer
When little pesky fish are active and you can't keep your bait on the hook, splitting the big and little fish apart can make it a lot easier to catch blackfish.
However be careful not to drop any attractant inbetween the your two points as shown below.