The Dee Why end of the Dee Why–Curl Curl reef is documented chiefly by the VIZ dive club, whose GPS survey covers the whole 1–2 km of reef between the two beaches, and it is the less rewarding half. Below the Dee Why headland and its ocean pool the reef is shallow – 8–12 m – a mix of kelp-covered rock, sand patches and small boulders that the club describes bluntly as 'not very interesting' for the first third of the southbound traverse. The reef gains structure and sponges as it approaches the Curl Curl end and the easternmost area, where it drops to 18–20 m, and for that reason the site is normally dived from the Curl Curl side or traversed end to end by scooter, with the Dee Why access used mainly when the swell direction favours it or as the northern exit.

That said, the headland reef has its merits on a flat day. Dee Why Point is a rocky promontory with deep gutters between the platform and the outer rocks where blue groper, luderick, bream and red morwong are thick, Port Jackson sharks shelter in winter, and the kelp holds cuttlefish, octopus and the occasional weedy sea dragon. Kingfish and Australian salmon run along the point in season, and eagle rays cruise the sand to the south.

Sponges and sea tulips begin to appear once the reef passes 10 m. The site is for experienced, self-sufficient divers: the entry is a surf-break platform, the lagoon outflow ruins visibility after rain, and anyone attempting the full traverse needs a scooter or boat support, a DSMB and ideally a PLB. Dive Centre Manly and Pro Dive Manly do not run it.

It suits scooter divers, VIZ-style explorers and locals who want to know what lies under the surf break; for everyone else, North Curl Curl and Freshwater give better value for the same swell window.

Dee Why Beach car parks are off The Strand (paid) with the ocean pool and headland at the southern end. From the pool, a rock platform gives an entry onto the reef in flat seas; otherwise enter from the southern corner of the beach. The reef runs 1–2 km south to North Curl Curl and the interesting sections are far from this end, which is why the VIZ club recommends a scooter or a boat (Manly boats reach the Dee Why headland in about 15 minutes).

Exit at the pool platform or beach; an emergency exit is North Curl Curl platform at the far end.

Dee Why Point is a well-known surf break, which tells you everything: the reef is a wash zone in any swell over 1 m and the platform entry is dangerous when sets are running. Only dive it on flat mornings with a westerly. Dee Why Lagoon opens after rain and pours brown water straight across the reef, so allow several dry days.

A documented rip runs off the northern end of Curl Curl beach at the far end of the traverse. Take a DSMB and PLB for the long swim, and expect surge everywhere shallower than 10 m.

Enter beside the pool, descend to 8–10 m on the kelp reef and head south with the reef on your right; the first third is shallow sand and low rock, then boulders and ledges appear and sponge cover increases toward the sand line at 12–14 m. Turn at a third of your air (or scooter battery) and return north along the same reef, exiting at the pool platform in a lull.

No regular operator; independent scooter divers, the VIZ club and occasional Manly boat drops on the headland reef.