putative Royal Tern photos on Stop Press look very good!
I was thinking the same.
The outer primary coverts and primaries are obviously of a different generation, and could indicate a second-summer or an adult; the generally pale plumage also seems good - Royal is pale when compared with elegans on specimens. Bill colour, length and depth seem pretty good too.
Shame it only showed for just over 10 people, of whom I was NOT one...
Seems to be talk that it would possibly be better for the west African race, due to the apparent bill thickness, but the validity of some of the criteria used to seperate both taxa, or even the validity of having two races of Royal, have been questioned in some quarters, as far as I am aware.