The cod will start to show any time now, just as the crab moult begins. Usan is patchy and tends to get fished out quite quick as most of the summer fish are resident. June and July are good months as long as the sea is settled and clear. Wrasse bay, Rumness and surrounding areas are always worth a go - I would rate them much better than Usan. Crab is the only bait you need, fresh or frozen.