User blog comment:JoshuaCoalskull/Calling All Testers - MORE WEEKEND UPDATES/@comment-1140008-20111105012224

There may have been some confusion about the Copperhead Feature. It IS NOT a new ship type. It is a rank for hull upgrade. It gives a 10 or 15% chance of explosives fired from your broadsides. For more about Hull Upgrades, see here.