If the cap fits you wear it.
So - given we have an area too large to patrol, too few resources to patrol effectively with no coordination, a wide range of targets that sail individually & an 'enemy' made up of foot soldiers with little to lose who can launch attacks from even small vessels and whose bosses aren't joining in the actual capture of boats....
Then the 'blow them up' doesn't appear to work.
I agree with Alfred though I'd also have to ask if it is completely out of the question for logistics companies who can tell you where your box is within a container on a ship & who seem to be able to coordinate their rates fairly well to be able to coordinate their ships in some way? So that the protection resource has less of an area and less potential victims to look after. If countries can not coordinate protection then those countries might have to consider how they are going to arm ships that pass through the area & if it is not worth while putting some form of security on the ships? Isn't that their responsibility?
Now that seems naive and expensive - but how expensive is it to pay ransoms and have crew held captive and expensive ships under the control of criminals? This didn't start this week - it's being going on for years. We hear how airlines and air transportation have had to pay and suffer inconvenience to deal with risks - so what are shipping lines doing?