How often does the shuttle run?

Every 30 minutes you have to book it its free if you are a guest last one back is about 9 pm

I've forgotten, try calling the Hotel.

Every 30mins

Every 30 minutes and you do have to book it, but they'll run it, even if its just one or two people

Every thirty mins but it's busy the driver comes straight back.

I believe it was every 30 min, but you have to book it (its free for guests), up until 9pm.