HMS Oberon reporting.
Iran
did sign the convention of UNCLOS, but has not ratified it:
http://www.un.org/Depts/los/conventi...on%20signature
There are a number of concerns it had, mostly more to do with its neighbours than with the likes of the US, back in the aftermath of the Iran/Iraq war. To be honest, if the US signed the UNCLOS it might actually be to its advantage when it comes to legal challenges in the Straits of Hormuz.
Oh, and in regards to Russkie ships passing through the Channel, it happens annually, I think even the Admiral Kuznetsov went through last year, probably to be near a port in case it broke down. It's nothing major, we usually just kick out a patrol boat, it comes over and says
Zdravstvuyte, tracks them in the waters to make sure they don't collide with a merchant vessel (which is a bigger threat than hitting a rogue missile whilst transitting the Channel) and then points them towards Murmansk or Syria when they come out the other side.
Now with
Gibraltar...that's a bit more complicated...