Complex sentence: It was discovered in "Derrynaflan Island" in February 1980, by Mr. Michael Webb and his son who were scanning the area with a metal detector, then a relatively new device on the market.
Split into simpler sentences: It was discovered in "Derrynaflan Island" in February 1980 by Mr. Michael Webb and his son. They were scanning the area with a metal detector, then a relatively new device on the market.