I've done a couple of Guadalupe trips. During the first trip (2016), I used my Nikon 10-24mm (rectilinear) and it worked very nicely. It's probably worth noting that, I spent considerable time hanging outside the cage during that first trip. I'm small so it was easy for me to slide through the viewing opening on the cage and keep one leg wrapped around the inside to retreat back inside if necessary. One large male did give me the 'staring into the Jaws of Death' experience near the end of our last day during that trip when he made a run to try to pick me off the side of the cage. I simply slid back inside to get out of his way. It happened so quickly that I didn't even give it much thought until I was reviewing and post-processing images. I didn't feel like I needed my strobes during the first trip. The curved field of view that a fisheye creates isn't something I care for; mine never came out of my gear bag.
As I prepared for my second trip, I added a Nikon 16-85mm to my camera bag. I felt like I had missed a lot of opportunities during my first trip because the 10-24mm didn't give me enough reach. Sometimes you have sharks that drop-by for close passes and others don't come in as close.
The second trip (2017) was good. I was happy with the 16-85mm and I used my strobes during some of my cage time. White sharks have blue eyes and it's difficult to get the color unless you can light them up.
One of the frustrations I encountered at Guadalupe was the screen of mackerel that take up residence under anchored boats. It was extremely difficult during both trips to capture decent images of the sharks with the number of mackerel that show-up.
Another minor irritation was the people who had their Gopro cameras on long sticks. I missed more than one opportunity for great image captures because a Gopro on a stick would appear in my viewfinder as sharks would come in close. Of course, this is one of those give & take things. Other divers are there to capture images and video too. Some of those folks were probably silently cursing the nut job who kept climbing outside the cage to pursue the images he was after.
Do plan to wear what you need to stay warm. Sometimes you have to wait long periods of time before a sharks decides to drop-by. It can get chilly if you don't have enough wetsuit.
If you're interested in looking at some images from my trips, check out the portfolio on my website www.cortezbluephotography.com.
-AZTinman