The Black rock was one of a number of second hand Scottish built steamers acquired by the Thomas family. She had been raised after being sunk by a steamer Balniel close to Liverpool bar.

She was brought to Amlwch, stripped down and modified. While in the dry dock a violent storm caused her to crash through the lock gates. She demolished the lighthouse pier and totally blocked the harbour entrance.

Following a refit she was renamed the Eleth after the patron saint of Amlwch.