I've had a look through the Warships1 board and from what I've read there's no comparison with what's being done to protect ships from Somali pirates, and others, with the very tight convoy system used during WWII. I note too that the French option is to offer what is referred to as Close Support Protection - having marines on board merchant ships. This suggests to me that the convoy system, such as it is, is not as tightly organised as I would expect. Probably the word 'convoy' is being used very loosely in the Gulf and Indian Ocean, etc.