Greenfield and Blenheim beaches in Vincentia are linked by the popular White Sands Walk and separated by low rocky outcrops that make for easy snorkelling. The Shoalhaven tourism body describes the area as having abundant marine life and gentle waves suitable for beginners, and Curious Campers lists Blenheim among the best snorkelling sites in the bay because of its rocky outcrops teeming with life.

The outcrops shelter the typical western-shore fish – blue groper, luderick, bream, leatherjackets, wrasse and small schooling fish – while the sand holds rays and flathead. In winter humpback whales migrate through Jervis Bay and can sometimes be seen from the beaches or heard underwater. Depths close to shore are shallow, so this is primarily a snorkelling venue, although a relaxed shallow scuba dive is possible on calm days.

Greenfield Beach has the better facilities, with parking, toilets and a picnic area, and is a good starting point; Blenheim is smaller and quieter. The beaches face east across the bay, so they are best in westerly weather and choppy in north-easterly winds. Summer crowds can be heavy. The area lies within the Jervis Bay Marine Park, and the White Sands Walk continues south past Chinamans Beach to Hyams Beach for those who want to explore further. Kayak hire in Huskisson and Vincentia makes it possible to combine paddling and snorkelling along this shoreline, and the bay's resident bottlenose dolphins are sometimes seen offshore. Water temperatures range from about 15 °C in late winter to 23 °C in late summer, so a 5–7 mm wetsuit is sensible for anything longer than a quick summer snorkel, and a hood helps from June to October.

Jervis Bay is about 2.5–3 hours south of Sydney via the M1 and Princes Highway, turning onto Jervis Bay Road at Falls Creek. Drive to Vincentia and follow the signs to the Greenfield Beach car park (toilets, picnic area) or to the smaller Blenheim Beach access. The White Sands Walk connects the two beaches.

Enter from the sand and snorkel along the rocky outcrops that separate the beaches.

Inside Jervis Bay the water is sheltered from ocean swell, but the bay is big enough for wind chop: strong north-easterlies (summer afternoons) make the western and southern shores choppy, and southerly or westerly winds affect the northern shore less. Diving is possible on most days of the year at one shore or another. Visibility is usually 8–15 m, better in winter, and drops after heavy rain when Currambene Creek and Moona Moona Creek flush tannin water into the bay.

Tides are small but high tide gives better visibility at the beach entries.

Enter at Greenfield or Blenheim and follow the rocky outcrops between the beaches, exploring cracks and ledges in 2–5 m, then return over the sand.

No scheduled guided shore dives; Dive Jervis Bay and other Huskisson operators hire gear and give site advice, and occasionally run training or snorkel sessions.