How to make a blockade work

How do you make coastal blockade missions register in the campaign?

Select individual ports and assign ships to blockade them; cruisers are particularly important for producing enough blockade effect.

Asked why destroyers spread around the coast are not producing a blockade result, the answer advises selecting ports and assigning ships directly to blockade duty. Cruisers make the difference in this campaign experience because they supply useful blockade capacity. A high-requirement province should also be blockaded before an invasion attempt so that the target is weakened first. The answer links operational orders to the larger campaign aim of reducing an opponent before committing invasion tonnage.