There was a group of about 6/7 of them flying off the coast of the beach, and they were diving.
No interactions present.
They look more Sandwichy to me, but I can't make out bill colour to be 100%.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
They were also very noisy, and I've just read that Sandwich terns are noisy ?!?
Structurally these do look more like Sandwich Terns than Common Terns (sort of more stretched, with a proportionally larger looking head). It is very difficult to be certain though.
All terns can be very noisy at times, so unless you can compare the calls that you heard with recordings and recognise the difference this won't be much help with the ID.
Lat/Lng: 54.41686, -4.37067
OS grid ref: NX462049