I think you are overly optimistic about how international shipping is run. All that stuff costs money and most ships are operated on an extremely tight budget, especially as shipping rates have fallen. I don't kow the wet side that well, but most owners don't spend more than $5k/day operating pretty dang big dry bulk ships, and that includes crew, lubricants, parts, stores, filters, maintenance, etc. Adding all the expensive security stuf would add very materially to that cost. That might be feasible with the nice, shiny new ships that are worth a lot. But the 20 year old freighters that make up a large fraction of the world fleet? I don't think so.
I'm sure you are right--this would cost a lot. It would likely only be worth it for high$$ trips and for those where alternate (longer-but-safer) transits were impractical.
Alternatives?:
Convoys. "Blackwater Maritime Protective Services" 10 PT Boats guarding 10-15 closely-spaced merchant vessels. Hmm--probably not much cost savings.
Go on the offensive: A bounty for pirates. Lots of guns for hire in Somalia. Making sure you were buying actual pirate carcases would be tough.
The social issues driving all this are huge. It's impossible to overstate the disfunctional hell on earth Somalia has become. I heard an interview with a young Somali male the other day, "A girl won't even look at me unless I am a pirate." It's the only way they have of making it. Lots to gain, not much to loose.
- 50,000 volt metal nets over the rails?