Affectionate sea turtle tries to nibble scuba diver's arm

Cameron is a seasoned scuba diver who has met a lot of sea turtles and other marine animals. He's quite unfazed by this green turtle's curious advance but he also knows there is a lot of power in the turtle's jaws. They are designed for crushing coral and tough underwater vegetation. The green turtle is munching happily on the algae that grows on this coral in Mexico. But she becomes curious about the arm that is tantalizingly close.
As the turtle draws closer and seems to be sniffing at his arm, Cameron looks the turtle in the eyes and shakes his head. The turtle is just too curious to resist and she opens her mouth in an attempt to have a little nibble. There is no aggression in the movement. The turtle is simply curious, or possibly seeking interaction with him. Cameron adjusts his buoyancy slightly and rises away from the turtle. She gets the message and drifts past, looking for the next algae bloom to snack on.
Sea turtles occasionally have hitchhikers, like this one. These fish are remoras. They hitch a ride on larger fish and animals, using a suction cup on their head to hold on effortlessly. This is a means of preserving energy. They ride on their host and break loose to eat the feces or fish scraps that are found in the water around the larger animals. These remoras cause the turtle no real harm, but they create more drag and slow the turtle down. The turtles will try to brush them off when they can. They are simply a minor nuisance.
Most scuba divers would consider a close interaction like this one to be a dream encounter. The turtle is completely undisturbed by Cameron's presence and the entire exchange happens at the choice of the turtle. Responsible scuba divers will avoid touching marine animals whenever possible.