Crayfish Bay is the last cove before the Cape Otway lighthouse, tucked between Crayfish Point and Seal Point on the eastern flank of the cape. Twenty to thirty metre vegetated bluffs back two small, steep beaches with no bar, and deep water lies right against the sand before the reefs begin 50 m out. The diving is around large underwater rock slabs, the deep gutters of the rock platforms and a group of bommies at the western end off Crayfish Point, in 5–10 m. As the name says, southern rock lobster are the local speciality, along with abalone, and the site is best known to spearfishers and cray divers who watch the forecast for the rare flat days. The heavy Southern Ocean water movement feeds a thick cover of bull kelp, brown algae and encrusting invertebrates, and schools of ocean-going fish – sweep, salmon, trevally – hunt the deep edge. Australian fur seals from the small colony at Seal Point, less than 200 m to the east, frequently swim through and will investigate divers and snorkellers, which is the site's extra attraction over the other Cape Otway coves.

It is the wildest of the four coves and the one with the least margin for error: deep water off a steep beach gives a heavy dumping shore break in any swell, the platforms take sweep from both directions, and the whole cape can change from calm to dangerous within an hour. The Scuba Doctor's advice is uncompromising – always go with a buddy, be extremely careful, and weak or average swimmers should not consider diving or snorkelling here. For a strong, experienced pair on a genuinely flat summer day it offers a memorable dive with crays, seals and big fish under the lighthouse, and it pairs with Point Franklin, which shares the same access track.

Take Lighthouse Road (C157) from the Great Ocean Road toward the Cape Otway lightstation and turn onto the same signposted vehicle track that serves Point Franklin, about 2 km short of the lighthouse; the track is dry-weather 2WD and rough. Park at its end and walk the short path down to the beaches. Crayfish Bay Beach is 150 m long and Crayfish Bay West Beach 70 m, both steep with no bar and deep water between the sand and the reefs 50 m offshore.

The best entry and exit is from the rock platforms toward the western end of the rocky beach, east of Crayfish Point. Around 32 km from Apollo Bay and 36 km from Lavers Hill; allow 3 hours from Melbourne.

Cape Otway is the most exposed headland on the Victorian coast and all of these coves face the open Southern Ocean or Bass Strait. Diving requires a day of exceptionally good weather: calm seas, no swell (under about 0.5 m) and no rough weather forecast, which in practice means summer and autumn under a high with offshore north to north-westerly winds; an offshore wind will flatten the sea inside the reefs. Waves average 1.5 m outside the reefs even on ordinary days.

Southerly through westerly winds and any swell over a metre make every entry dangerous. Conditions change quickly and a calm morning can be unworkable by midday. Walk to the point and look before gearing up.

Crayfish Bay sits almost on the cape itself, within sight of the lighthouse, and is the most exposed of the four coves; the Scuba Doctor calls it a highly hazardous area for experienced divers and snorkellers only.

Enter from the platform at the western end at mid tide and drop straight into the deep water between the beach and the reef. Work west toward the bommies off Crayfish Point in 5–10 m, exploring the big rock slabs and deep gutters of the platform, then turn at half gas and return east along the reef line to the entry platform. Seals from Seal Point, 200 m east, often investigate divers – let them come to you.

No operator – experienced local shore divers, snorkellers and spearfishers only.