Irish freediving safety diver and co-owner at Dahab Freedivers. He held several Irish national freediving records and was a Chief of Safety at various freediving events such as Vertical Blue Freediving Competitions.

Keenan died during a rescue in an attempt to assist freediver Alessia Zecchini to the surface from a depth of 50 metres in Dahab's Blue Hole in 2017. It was the first recorded death of a safety diver in action in freediving history.Before this he had successfully rescued Alexey Molchanov from a depth of 40 meters while putting himself in mortal danger and was regarded by many as the best safety diver in the world.