I'm trying to find the name of a series I read when I was younger. I suspect that it was originally meant for young teenagers even though I was probably around 7 or 8.

I don't really remember a great deal about it - it's a series about friends at a girls boarding school. One of them is a tennis player and one of them is a violinist.

I recall it being a bit Enid Blyton/Chalet School-esque but I think it was set rather later then those, 60's or 70's (maybe even 80's).

There was also a boys school nearby and some of the girls had boyfriends from there.

I vaguely remember there being a plot about running along a beach (or maybe out to an island) and the tide coming in and one of the less sporty girls getting stuck?

Has anyone got any ideas based on my not-very-useful memories?

This sounds like the Trebizon series by Anne Digby.

This sounds like the Trebizon series by Anne Digby.

Yes! That's it.

Thanks ever so much, it'd been driving me mad not being able to remember/find it