In the crystal waters of the Bahamas, diver Eli Martinez can make a Tiger Shark roll over with a simple touch.
The 41-year-old has, who traveled to the Bahamas several times a year for the past decade, has built a relationship with the Tiger Sharks which now get so close that he can rub his face against theirs.
He said: 'They are wild animals so you can never get 100% comfortable - they are deserving of the respect the other divers and I show them.
'I've been going to the same spot for the last 10 years and after a few repeat interactions they know the drill but I must not forget what they're capable of.'
"We're usually surrounded by two to four tiger sharks plus around 40 lemon sharks and close to 60 reef sharks - they're a bit smaller and more feisty but you have to respect them all the same."
He added: 'I'm able to get them to roll 180 degrees in the palm of my hand.
'They are really calm creatures unless they feel threatened so it's important none of us did anything to alarm them - they know we are not in the water to harm them.'