Boating Warning: Dangerous Sydney rockfall along North Head

A massive rock fall along the towering cliffs at inner North Head, one of the sandstone sentinels standing guard at the entrance to Sydney Harbour, has prompted maritime authorities to issue a warning to boaters to steer clear.

Visiting this exact area on Monday August 8, 2016, your Marine Editor can vouch for the fact the cliffs were standing tall and holding their defiant structure earlier in the week.

Our Editor adds that he even spent time at the outpost 100 metres before Fairfax Lookout, which would put him just 100m away from this rockfall between Fairfax Lookout and Old Man's Hat, which is halfway along the south-facing headland. The second photo above was taken from this location on that morning.

But a few days after our visit, on Wednesday August 10, charter fishers and maritime authorities were warning of a massive rockfall along this popular trolling 'highway' at the entrance to Sydney Heads.

Todd Adamson, one of NSW Maritime's Boating Safety Officers, photographed the rockfall at North Head 300 metres west of Fairfax Lookout. It appears huge sections of sandstone have tumbled into the sea. Imagine the power behind all that sandstone.

NSW Roads and Maritime said, given the area now appears to be quite dangerous and unstable, it is advising boaters and fishers to stay away from inner North Head.

Presumably, geologists and surveyors will need to ensure the area is safe, especially given the amount of foot and boat traffic to the area.

There have been some massive Sydney storms in the last few years, with an intense East Coast Low in June 2016 that caused widespread coastal damage and to boating infrastructure, and another destructive storm in late August 2015 that wreaked havoc on the city.

Trolling the washes along North Head is a popular and productive small-boat fishing strategy, while the rock-fishing ledge called Old Man's Hat just a few hundred metres further inshore is a legendary spot (albeit highly dangerous in a southerly).

Fishing the cliffs around Sydney is a tradition that goes back to colonial times. Along with watching the waves, those fishing around Sydney's porous sandstone cliffs needs to be aware of rockfalls.

There was steady rain in the lead-up to the rockfall and North Head is saturated with creeks, ponds, soaks, wetlands (perhaps with questionable drainage) and ambient water being absorbed by the Sydney sandstone. More on these kinds of events at NSW Community Alerts.