At least for the Chesapeake. 7lbs, biggest I've caught in the Bay in years, maybe my biggest ever...
Caught him on a deciever fly. These blues were eating 12-14" rockfish. We would see a few random splashes, and a gull or two screwing around and go over to find a rock bitten in half, and a blue or two underneath just picking chunks out of them. It was pretty wild. Found them between 72 and Hollands Island in 25-30' of water.
The fish were not holding onto anything, and seemed random, other than if you found some breaking on the surface, you would usually see or hear another random predatory splash in the proximity (within 100 - 200 yards) every minute or so. I even saw one of the chunky son of bitches jump clear out of the water. When they were breaking, they would be up for just long enough for me to fire up the boat and try to get a fly on them before they would disapear again. I think just casting a big popper out and slowly popping it back in an area where you find them marauding would result in some hookups. I got impatient trying to chase the random splashes, and gave up at dark to find rockfish for my dinner (which I did, nice 25" in 3' of water at the mouth of creek on an outgoing tide, I was in a hurry to get home before dark so I put away the fly rod and caught him on a BKD), so I did not put the theory to a test, but will try it as soon as possible.