Fished down to the tuna pens east of the Hidden for several patties with yellows along the way. The tuna fishing sounded pretty slow for everyone except those fishing down in the Lower 500 range. Late in the day making our way back up the line we found birds working in the south end of the trench just west of the Coronados (16/18). We trolled after the birds for at least a mile and they just wouldn't let us catch up with them. I was saying it seems like boat shy bluefin under them when we finally got our jigs into the zone and a troller went off. A nice 40 lb class BFT! Got 4 more in the area, all on a blue mack x-rap 15.