I'll have to give you SOLAS, I don't have a copy available.
The first specific reference to 'naval auxiliary' in UNCLOS reads like an "exemption to some degree" to me. Perhaps I should have said "exempt from their provisions" rather than "exempt", which I can see might have been interpreted as meaning a blanket exemption..
No it does not provide a blanket exemption. What UNCLOS does is provide the legal frame work covering warships, ships owned and operated by the government as well as other vessels.
Did you read the application of article 236. It only covers the preservation of the marine environment and is really only applicable to the high seas. It allows warships and ships owned and operated by the government the right of sovierign jurisdiction given their diplomatic status. I note you missed the important second part to this:
However, each State shall ensure, by the adoption of appropriate measures not impairing operations or operational capabilities of such vessels or aircraft owned or operated by it, that such vessels or aircraft act in a manner consistent, so far as is reasonable and practicable, with this Convention.
I also note you did not look at the status of such ships in territorial waters and I would point to article 19.(2).h where all ships, including warships, are not permitted to commit any act of willful pollution.
In short in so far as blanket exemption is concerned this is nonsense. I suspect you simply did a word search and have extrapolated your blanket exemption from that.
Bay class are all certified as passenger ships, as the LSLs were before them. The remainder are certified as cargo ships but carry embarked military personnel in excess of the 12 passengers at the MoD's whim with an occasional reference to a safety case. I've sailed on every class of RFA in service and none of them are SPS.
I think we're really just arguing about your application of the term "commercial" to a non-commercial government entity as opposed to the more encompassing "Merchant".
Where is "troopship" defined? I've not seen a definition before and I'd quite like to.
Passenger ships, yep looked tham up and found this
They are built to Class 1 Passenger Ship Certification commercial standards and classed by Lloyd's Register.
Better option that SPS as it means the person carried do not have to be associated with the fucntion of the ship and makes them better for disaster relief. However, this again relates to 'trading' certification. I note the comment with regards to "merchant" but Just what do you think the term Merchant applies to.
A person or company involved in wholesale trade, esp. one dealing with foreign countries or supplying merchandise to a particular trade.
If you don't like the term commercial then accept cargo ship........ but the Bay class are still subject to non-military certification and is under the jurisdiction of the civilain regulator.
Ships can be declared troop ships by the flag state. It absolves them from the requirement to comply with the requirements of SOLAS for the numbers they carry in this role.