Sark is also worth a visit whilst your kicking around!
By the time you've finished you'll need 6 weeks holiday!!
I'll come out and say hello if I'm around at that time and show you a couple of rocks you need to watch out for going through Percee Passage in between Jethou and Pt Sauzebourge on Herm. Tinker is one and I can't think what the other one is called but they lie opposite to each other a couple of hundred meters apart.
It is a little "Tinker" as well! It sits just below the surface and isn't marked. Quite a few boats give it a nudge during the summer months!!
Anyhoo sounds like you'll have a cracking weeks ribbing!