Sure - as previously put to you - how does Coral suffer being underwater during the flood.
because
quote:This is because Coral grows at the water's surface. If you Flood the earth at a rate faster than the coral is able to grow, you would kill it. Coral growth is similar to tree growth, in that their growth varies over the year. This means that coral have "growth rings" similar to tree rings. Furthermore, the yearly coral rings have a line structure due to both daylight and tidal variations.
Any drastic change in the growth rate of corals would be obvious in the ring pattern. Ancient fossil coral display growth rings very similar to those of modern corals. Conclusion: their rate of growth was not notably different from that observed today.