Outer Corsair Wall is the seaward continuation of the Nepean-side cliff, the last named section before the wall runs out into the open floor of Bass Strait. The Scuba Doctor listing describes it in the same terms as Inner Corsair – 'a very spectacular wall dive with lots of ledges, caves and drop-offs' – with the top at 10 m and the base at over 65 m, and it notes that it is a good crayfish wall. It lies only 32 m from the Rip Bank mark and the two are, in practical terms, one long face; a charter that calls a dive 'Rip Bank' may well put divers on this section.

The wall is the most exposed of the Nepean group. The shallow top is kelp and broken rock, and below the lip the face drops in long vertical sections with big overhangs and caves at intervals; the encrusting life is dense and the fish are those of the open coast as much as the bay – schools of sweep, boarfish, blue devils in the caves, sevengill sharks off the wall, and seals overhead. Visibility here is often the best at the Heads because the water is straight from Bass Strait.

That exposure is also the limit. The listing states that it 'can only be dived on slack water as it is only just out of The Heads', and in practice it is dived on the end of the flood in calm seas so that the returning ebb – which sets straight out to sea – is not running while divers are still in the water. It remains technically inside the shipping channel. This is a site for experienced Heads divers with a skipper who knows the entrance; technical divers value the 65 m base. Recreational Advanced divers can dive the top third on a short, disciplined profile when conditions allow, but it is not a regular charter drop.

Boat access only. Charter boats leave from Portsea Pier (Dive Victoria Group, Bayplay) and Queenscliff Harbour (Dive Victoria Group, Red Boats); run time is about 15 minutes. Private boats launch at Sorrento Boat Ramp (Point Nepean Road, Sorrento, all-tide concrete ramp with trailer parking) or Queenscliff Boat Harbour ramp (Larkin Parade, Queenscliff), roughly 18 minutes to the site.

The site is at the seaward end of the Nepean-side walls, immediately south of Rip Bank; technically still in the shipping channel although ships do not normally cross it. Skippers must call Lonsdale VTS (Point Lonsdale) or listen to VHF 12 for shipping movements before dropping divers, and must carry a dive flag; anchoring is not permitted in the shipping channel, so a live boat and a drop-shot or drift float is the normal method.

It is dived only on slack water at the end of the flood (SWF), so that any current after the turn carries divers back into the bay rather than out through The Rip. Slack water at Port Phillip Heads does not coincide with high or low water: it falls roughly three hours after high or low water at Point Lonsdale, and the usable window is typically 20–40 minutes. Use the Ports Victoria / Port of Melbourne slack-water predictions for The Heads (also republished by charter operators and WillyWeather 'Rip Bank') rather than a standard tide table.

Being outside or right at the entrance, it is exposed to Bass Strait swell: anything over about 1.5 m from the south-west or south, or a strong southerly/westerly wind against the ebb, produces standing waves in The Rip and charters cancel. Northerlies flatten the entrance and give the best days. Visibility is best in late summer and autumn (Feb–May) when the water is clear and the westerlies have eased; winter brings 11–13 °C water and bigger swells but often the clearest days after a run of settled weather.

Heavy rain has little effect this close to the ocean. The listing states it 'can only be dived on slack water as it is only just out of The Heads'; because it faces open water the end-of-flood slack in calm seas is the only sensible choice.

As for Rip Bank: shot onto the 10–16 m top at the end of the flood, drop the face to the planned depth, follow the ledges and caves for 15–20 minutes, return up the wall and ascend under DSMB as the ebb begins, with the boat tracking the float.

Base 65 m+; flood slack only, calm seas; trimix; drift deco under DSMB with a tracking boat; the ebb sets seaward.

Dive Victoria Group (Portsea/Queenscliff) – runs the deep Heads walls for advanced and technical divers on suitable slack-water days; Red Boats (Queenscliff) – deep-wall and technical charters on request; otherwise private club boats (VSAG, Power House Underwater Club, Scuba Diving Melbourne). Not a routine training-boat site.