The Impulse Flex uses a revolutionary mechanism in the top of the snorkel that closes on descent, keeping your snorkel dry.

The Impulse Flex uses a revolutionary mechanism in the top of the snorkel that closes on descent. Provided you keep your mouth closed no water can enter. This means as you ascend the snorkel is totally dry ready for you to inhale. Any small amount of water that may enter is drained through the large exhaust at the bottom.