No one was building iron hulled ships until the 19th Century.

The Kyrennia ship however, does show that in at least some cases the Greeks used Lead sheathing on the outside of their vessels.

This report, in pdf, discusses some of the uses of the sheathing as the wreck was being examined to create designs for a replica.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCMQFjAA&url=http%3A%2F%2Fkyrenia-collection.org%2Fresources%2FPDF_Files%2FNGS-Research-Report-1972-5-vol-13.pdf&ei=n7KVU-_YFYmSqAbexoHIAg&usg=AFQjCNGowFC1bTrjb8vuDQE_iXa8kUPI-w

The Byzantine fleets sometimes used greek fire. However the precise mechanism used is still being debated.

The 300 series is not, nor should ever be considered, historical. It is a deliberately inflated retelling of several myths.