On the deep shipping canals of Yorkshire that I fish, loosefeeding over the top of groundbait actually defeats the point of what I’m trying to achieve. I want the fish to be firmly on the bottom, feeding on the groundbait and giving me a focal point over which to put my rig.
Firing in casters or maggots runs the risk of spreading the fish over a wider area and even coming off bottom, so I wouldn’t use a catapult at all. Instead, I’ll cup in two to four balls of groundbait, the amount depending on how many fish I feel are in the area and how good the peg is, topping up with a ball the size of a large walnut when bites fade or I begin to catch small fish.