To mark Shark Awareness Day 2016, we look at some lesser-known facts about the species.
“When you see they are really not there to eat you but just curious like we are... it allows you to totally relax and just enjoy their company.
“Sometimes I will go into the cage even without my camera just to hangout.”
Great whites, made famous in the film Jaws, are one of the largest species of shark and among the most feared.
Mr Rannachan added: “The benefit of Guadalupe is the water visibility.
“On a good day it is staggeringly clear, lending itself really well to photographing sharks.”