The viewing platform at Jacks Blowhole
As with the bay and nearby island, Jacks Blowhole is named after the famed Ngāi Tahu chief, Tuhawaiki, known to early European settlers as Bloody Jack - apparently he was fond of using the expletive. The route to the blowhole is marked by painted poles. Follow them, use the stiles rather than the gateways, and respect the access provided by the landowner.
The blowhole is in Tunnel Rocks Scenic Reserve. At 55 m deep, some 200 m from the sea, it was formed when the roof of a large subterranean cave was eroded by the sea and fell in. This is an exposed coastline and heavy swells from the southern ocean can create an impressive display. The waves are compressed through the underground tunnel and explode into the blowhole. There's plenty of roaring sound effects from both the water and an onrush of air, created by the surge from the sea expelling the air from the tunnel.
Walking across farmland to
There are also excellent views from this headland; with the broad sweep of the coastline down to Penguin Bay and beyond a feature.
For your own safety, do not lean or climb over the fence around the blowhole.
From the Southern Scenic Route, follow the signs to Jacks Bay and the carpark.