Port Alfred on trials.

I would dispute the location as being off the Arran Measured Mile.
Both photographs are from original Port Line Postcards taken during trials by the builder, Harland & Wolff, Belfast.
You can see the Builders Flag and Pilot Flag.
I might suggest that the location is off the Antrim coast.
Other Port Line Postcards depicting Belfast Built Ships were taken in Belfast Lough with the ''Cave Hill'' in the background.

Thanks for the correction on location Portred - I was always of the belief that Harland & Wolff, Belfast sent their trials jobs to the Arran Mile but obviously not.
Indeed both photographs are from the Port Line postcards of the day, I'm in possession of them and quite a number of other Port Line postcards from my time in the company.
The H & W flag is very apparent - however, the flag on the starboard yardarm is not the pilot flag ("H&quot but code flag "A" (white at the hoist, blue with a swallow tail at the fly) which in those days carried the meaning "I am carrying out speed trials". Today, code flag "A" indicates that a diver is operating from the location displaying the flag.
------------
Mike.