The GT’s are there right now, this pic was taken by Ian Banks on Sunday. They will only come up to the surface if there is sufficient bait to warrant it. Are you seeing large schools of baitfish coming in with the tide? If not, then you may have to troll for the GT’s in the Northern Y, microjig the pipeline, or find them on the bottom at night either in the Northern Y or end of the North Wall on a run out tide and run a plastic through them. 