Do you need to prebook a trip or can you just turn up?

Best to pre book to guarantee a place, but you can just turn up. It's a long drive to it if they have no time slots available. Well worth it

Woyld recommend prebooking for thr hour long tours - there were only 30 min ones left when we arrived

You can just turn up, but you might have to wait a while if they are busy and the next boat is booked full

Turn up but do it early in the day as you may have to wait.

You can just show up.