The dark hole rests in the shallows of a bright blue reef shelf. The best corals are over the saddle at the furthest point which are normally accessed by entering further north down 'The Bells' - a 30m deep crevace (great experience). You pop out at 30m alongside a vertical wall reef which is incredible. Swimming along to the blue hole the view is incredible. Keep an eye out into the blue for whale sharks, skarks and manta rays. When in the Blue hole watch your depth as hundreds have died there from oxygen toxicity and diving too deep.