Boarfish Reef Drift is the drift-dive version of the Lonsdale Bight reefs, run from a float line over the eastern part of the Boarfish Reef area off Shortland Bluff. The Scuba Doctor listing gives a depth range of 6–32 m, rates it Advanced Open Water, and explains the method that Port Phillip operators use for drifts: divers are organised into groups on a roughly 50 m rope with a buoy and dive flag, the rope is arranged parallel to the current, and the boat follows. 'This is really the easiest form of diving as very little kicking is required or navigation – just go with the flow!'

The ground beneath the drift is the same as Boarfish Reef proper – broken limestone outcrops, sponge gardens, kelp patches and sand gutters – but seen at the pace of the tide, which turns a reef dive into a passage over several hundred metres of bottom. Long-snouted boarfish, magpie perch, leatherjackets and blue devils appear and disappear as the reef changes, crayfish are spotted in the ledges as they pass, and rays and Port Jackson sharks lie in the gutters. The 6 m end of the range is the shallow kelp near the bluff; the 32 m end is where the reef falls toward Spec Reef and the channel.

The listing notes that Port Phillip drift diving differs from most places because of the strength of the current and the volume of boat traffic, which is why the float-and-flag routine is not optional: a drifting group without a flag in Lonsdale Bight is in the path of the ferry, pilot boats and the fishing fleet. Operators run it on slack or on a gentle flood or ebb, and it is a popular second dive after a wall, being easy, relatively shallow and long. Shortland Bluff Bommie lies 100 m away and is often the start point.

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 10 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 8 minutes to the site.

The site is off Shortland Bluff on the Queenscliff side, 8–10 minutes from Queenscliff Harbour. 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. Drift diving here is done in groups on a roped float: divers descend a ~50 m line with a buoy and dive flag, the line is oriented parallel to the current, and the boat follows the float.

It is dived only on slack water, either at the end of the flood (SWF) or the end of the ebb (SWE); most operators prefer the flood slack so that any residual current sets into the bay rather than out to sea. 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.

Inside the Heads it is sheltered from most swell, but a south-west swell over about 2 m still surges across the top of the wall and a westerly or south-westerly wind over 15–20 knots makes the boat work unpleasant; big seas outside drop visibility to a few metres for a day or two. 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.

Listed for slack water, but as a drift it is also run on the early flood or ebb when the current is 0.5–1 knot; strong springs are avoided.

Group descends together on the float line to the reef at 12–18 m. Hold position on or near the line, let the tide carry the group across the reef, sponge gardens and outcrops, and use the float as the reference for the whole dive. The line is shortened for the safety stop and the boat retrieves the group from the float; no navigation is needed – 'just go with the flow'.

Dive Victoria Group (Portsea and Queenscliff) – double boat dives to the Heads walls most days of the week, site chosen on the morning by slack-water time and swell; Bayplay Adventure Tours (Portsea) – weekend and holiday charters; Red Boats (Queenscliff) – weekend Heads charters; Melbourne clubs (VSAG, Power House Underwater Club, Scuba Diving Melbourne) run their own boats here regularly.