Some excellent input above.
It's worth considering a couple of factors - such as the speed of current, and the tidal rise and fall, and weight of the berley basket. I remember reading in a good book on snapper fishing that current is usually slowest right on the bottom, so it's best to drop the bomb to the bottom and pull it up a few metres - where the current is strongest.
But that approach means that in a 3m tide variation day, you should re-set the berley a few times during a session.
Obviously if you have a plastic berley basket, that won't get to the bottom like a wire basket. You will likely need to use some weights - e.g. a hapuku sinker - to get it down. And the faster the current, the more weight needed to keep it vertical.
And if you set berley in a strong current on the surface, the berley may never get to the bottom, rendering it a waste of time (and money).
And the type of berley can make a difference. Some tries to float, while the stuff with mussel or kina shell in it sinks much faster.
I was once told not to attach the berley to the anchor line as the current can take the berley in a cross direction without you realising, and if you stick to fishing out of the stern, you may completely miss the fish attracted to the berley.