NOVA Online | Island of the Sharks

To help the seal, you have to understand how scientists believe a shark's senses might work together. All six senses are important, but a shark relies on some more than others, depending on how far away the prey is.

Hearing—The first signal a shark detects is often irregular, low-frequency sounds made by an animal in distress. The shark turns and moves in the direction of the sounds.
Smell—As a shark swims, it senses the odor of prey and continues upstream, crisscrossing the odor trail.
Vision—When a shark is close enough to see the prey, it can better judge the prey's location and whether it might be an acceptable meal.
Feel—As a shark moves even closer, its lateral line sense helps it to detect the prey's water movement. It might also feel the prey directly by bumping it.
Electroreception—At very close distances, a shark detects the location of prey by sensing its electric field.
Taste—At the final moment of attack, a shark often takes an initial bite, or simply "mouths" the prey without biting, to decide if it is edible.

OK, here's where the seal needs you. The shark has heard and smelled the seal and is just starting to detect its movement in the water. You're in a small motorboat next to the seal. What do you do?