Northern Arch

Northern Arch is the Poor Knights at their most vertiginous: a slot cut clean through the headland, walls sheer on both sides, the floor far enough down that clear water plays tricks on the depth gauge. In late summer short-tail stingrays assemble here, stacking in the arch in loose formations that can number dozens, with kingfish spiraling above them. Orca occasionally arrive to hunt the same rays, which empties the arch faster than any dive computer alarm. Even without the megafauna, drifting the walls among sponge and jewel-anemone color is a top-shelf dive; with them it becomes the story of the trip.

您此行的高光时刻: Stingray squadrons in summer, sheer walls through the headland, occasional hunting orca

地形地貌: A deep vertical slot through the headland, walls dropping to about 40 m

水流: Flow funnels through the arch; crossing it can mean ducking into the lee of the walls.

危险因素: Depth deception in clear water and funneled current; plan the dive shallower than the arch invites.

保育: No-take reserve rules apply; give aggregating rays space and never block the arch ends.

高氧（Nitrox）: 在此值得使用——各潜点深度落在富氧空气（nitrox）能有效延长免减压时间的区间（前提是持有相应认证）。