In 1788, a number of investors associated with the Parys copper mines formed the Amlwch Shipping Company, which was operated from the port or over 30 years.

Coal was imported and ore, sulphur and slag were exported. Such was the demand for improved and extended facilities at the port that an Act of Parliament was passed on 21 June 1793 for "...enlargement, deepening, cleansing, improvement and regulation of the harbour."
 

 
The regulation of the harbour was under the auspices of a Board of Trustees which was given powers to levy rates and duties from the owners of vessels using the port. One problem to be addressed was the damage caused to the harbour by high seas resulting from strong northerly winds. The problem was partly solved by building two short piers opposite each other, across which timber was lowered into slots, to form a barrier.