Equip full scuba so the flippers make you faster. Swim away from the shark backwards in a circle, Nothing but head shots and a quick take down with cross bow and tranq arrows if you do this correctly. Their turn radius is pretty small so if you can keep moving so they ate pertually turning, it's an easy take down without any damage.
These are actually really easy to tame. Find one and lure lure it closer to the shore and then just stand on land where u are safe and keep shooting it. Make sure there are no other sharks or mantas that can hurt you while taming your shark. Good luck