Now that ships cost less the Union has the option to establish a blockade. The rules are somewhat unclear as to whether "frigates" are "ships" in the sense that they qualify for blockades.
each USA ship has a 10% chance to destroy a blockade runner located in its province. (p.81)
--50% or more of CS ports blockaded by fleets of at least 30 Strength (in ship units)
--100% of CS ports blockaded by fleets of at least 30 Strength (in ship units) (P.96)
For example, if the USA has fleets containing at least 3 ships each blockading 50% of the CSA’s ports, then the CSA receives 50% of the normal resources and research from the European Powers.(p.109)
