Chumming or berley as we call it here, is a recipe for success. Ground up fish by-products generally constitute a berley bomb. Frozen bombs range in size from 1.5 to the big bertha 8kg bombs. Berley bombs can contain anything scraped up from the fish factory floor, all blood and guts. Sophisticated bombs contain a heathy mix of Mussel, pilchard, salmon or skipjack, often the minced in a Bolognese of unidentifiable mush. Good berley should be oily as this carries on the current to attract fish and also triggers them to feed. To much berley is not always a good thing, if you give too much you are feeding the fish, effectively becoming your own competition.
Chumming is mostly done at anchor, or land based, the key is to make sure you are actually fishing in the berley line, wind and tide direction can sometimes have you fishing in empty spot.
Attracting and triggering the fish to start feed is the what i's all about, after a few hours of constant chumming the fish should bite inhibited in a frenzy…or not
Berley is often set just of the bottom and dropped in a weighted pot or cage with holes to let the ooze out slowly. In shallow water a transom mounted berley pot with a masher works treat, with the added bonus of the smell on a hot day.
There is also an etiquette to chumming, if you suspect a boat is the chumming, don't anchor directly behind it , you likely will be right in there berley trail and become the recipient of some colorful sign language.
One thing is for sure, if you want to catch more fish at anchor it pays to broadcast your presence, get good oily berley apply sparingly and hand on.