Little Waterfall Bay is the smaller neighbour of Waterfall Bay, a cove where a second creek drops off the cliffs of the Tasman Coastal Trail. Go Dive Tasmania lists it as one of its regular boat sites, describing colourful reef walls and sponge gardens in 8-24 m with great visibility and a good chance of weedy seadragons. The topography follows the Waterfall Bay pattern: vertical and stepped dolerite walls at the base of the cliff, boulders and ledges below, and patches of sand at the deepest point.

The deeper faces carry sponges in reds, oranges and yellows, sea whips, hydroids and patches of jewel anemones, while the shallows are cloaked in brown algae and kelp where seadragons feed on mysid swarms. Because it sits slightly further along the coast, Little Waterfall Bay tends to be less busy than the main bay and gives operators another sheltered option when the offshore pinnacles are unworkable. It is a comfortable dive for Open Water divers who stay shallow, and a better one for Advanced divers who can use the full depth range to explore the sponge gardens.

The fish life reflects the protection of the area: butterfly perch and bullseyes, banded and magpie morwong, several species of wrasse, leatherjackets and the odd rock lobster in the cracks. Photographers will find the combination of seadragons in the shallows and sponge walls deeper rewarding on a single tank. Visibility is generally good because the site is washed by clean coastal water, although heavy rain can put a tannin layer on the surface near the creek mouth.

The cove is best treated as a relaxed second dive after Cathedral Cave or one of the deeper offshore sites, with a long, shallow finish in the kelp.

Boat access only. Drive from Hobart on the Tasman Highway to Sorell, then the Arthur Highway through Dunalley to Eaglehawk Neck (about 75-80 km, 1 hour 15 minutes). Eaglehawk Dive Centre is on Pirates Bay Drive above the bay; divers kit up at the centre and the catamaran leaves from the Pirates Bay jetty/boat ramp at the northern end of the Neck (Old Jetty Road).

Go Dive Tasmania meets at The Adventure Lodge in Taranna and launches at Eaglehawk Neck or Port Arthur depending on conditions. Little Waterfall Bay is about 10 minutes south by boat from Pirates Bay, past Tasman Arch and Devils Kitchen; boats pick up a mooring or hover in the lee of the cliffs.

Waterfall Bay is the most sheltered part of the Tasman Peninsula's ocean coast and is the site operators fall back on when the Sisters and Hippolytes are blown out, because the bay faces east-north-east and the high cliffs block westerly and south-westerly winds. It is cancelled by easterly and north-easterly winds and by large south-easterly swell wrapping into the bay, which drives heavy surge into the caves and gutters. For cave and swim-through dives the swell needs to be small (well under about 1.5 m) or the surge becomes dangerous.

Heavy rain turns the waterfall on and can put a fresh, tannin-stained layer on the surface for a day or two. Late summer and autumn give the calmest, clearest conditions; winter mornings with westerlies are often excellent.

Drop near the southern headland, descend to 18-22 m where the sponge gardens are richest, and follow the wall back into the cove, rising gradually. Search the kelp fringe at 8-10 m for weedy seadragons before a safety stop in the shallows.

Go Dive Tasmania – lists Little Waterfall Bay (8-24 m, Open Water to Advanced) on its Tasman Peninsula boat days from Eaglehawk Neck; Eaglehawk Dive Centre – used as an alternative Waterfall Bay site.