Call of Cthulhu: Incident on Bell Island

The liberty ships of World War 2 were hastily constructed cargo ships that moved desperately needed supplies from North America to Europe. They were built in weeks and many sank. On one ship, the Bell Island, the crew finds an alien stowaway that is seeking to take over.  Can the menace be stopped in time? This scenario was run at Gencon 2010 and was created and run by Tom Church.