Medusa, the fourth ship of her name to serve in the Royal Navy,Colledge, p. 221 was ordered on 10 March 1838, laid down two months later at Pembroke Dockyard, Wales, and launched on 31 October of that same year. She was completed on 12 August 1839 and had been commissioned four days earlier. The ship was initially based at Liverpool for packet service in the Irish Sea. Medusa was modified in 1848 for service in the Mediterranean Sea.
