Originally Posted by mmarsh

Where the Gun crews on Merchant ships Marines or Navy? I know they were Marines on the Capital ships (Carriers, Cruisers, Battleships), etc. But on Merchant ships I think they were Navy but I cannot remember.

Marines had "Marine Gun Mounts" one or two secondary (5 inch) turrets on Battleships and sometimes on cruisers. While most Marine Ships Detachments were trained on the ships guns the gun mounts were manned by Navy Gunners Mates except the designated Marine mounts.

Guns on armed Merchantmen were manned by Navy Armed Guards who were Navy Gunners Mates.

Originally Posted by Grimmy

Iirc there were some escort carriers. Those were former merchant ships converted into light capacity flat tops. Their primary purpose was to provide some protection to merchant convoys.

I do not recall if the UK had any carriers in the Atlantic area.

The USS Ranger was a fleet carrier and it was in the Atlantic. The Saratoga was too for awhile but they pulled it out to the Pacific when the Yorktown was sunk. But yeah, most of the US carriers in the Atlantic were jeep carriers. It wasn't a carrier war there though. Carriers were used in anti-sub roles in the Atlantic.

As for the UK well check the story of such names as HMS Ark Royal, Eagle, Glorious, Illustrious, and many more. They were vital to convoy duties for them. Malta would've been lost without the British carriers.