This is the most famous of the muck sites and one of the four most-dived sites in the Strait. The sand slope here is exceptionally rich. The position on a point means that the mix of currents brings more nutrients than on most other nearby sites. Hairball 1, 2 and 3 are named so for two reasons. First, a diver lost their hair band mid-dive, causing their hair to flow freely, and second, the algae there is said to resemble a cat's hairball.