I attempted to book a September 2016 Guadalupe trip on the Nautilus Explorer (sister boat to Nautilus Belle Amie) a while back, but the trip I wanted was already full. This particular boat does advertise allowing divers to climb on top of suspended cages when conditions permit.
Since the trip I wanted was already full, I booked with the M/V Islander out of San Diego. The Islander has a good resume of clients. We'll see how the trip goes in September 2016.
If there's a particular target week for when you want to go, book early. It sounds like the trips consistently fill. I thought I was attempting my booking with the Nautilus Explorer early enough; it wasn't!