Newhaven Jetty is the working fishing pier on the Phillip Island side of The Narrows, the 300 m wide gap that separates the island from San Remo. Everything about the dive is dictated by the tide: the whole of Western Port's eastern arm drains and fills through this channel, and Scuba Doctor records streams of up to six knots swirling through the pylons. At slack water, however, the same flow has produced a jetty dive of surprising richness for such a shallow, unassuming structure.

The pier runs out from a small beach beside the boat ramp, with the inner pylons largely dry at low tide and the outer pylons standing in a dredged channel of about 10 m that the commercial boats use. Growth on the submerged sections is described as reasonable rather than spectacular: encrusting sponges, ascidians, tubeworms and hydroids, with the same pylon-dwelling fauna divers know from the Mornington Peninsula piers – seahorses, decorator crabs, leatherjackets, cowfish, and pipefish in the weed and rubble at the base. Rays and flathead lie on the sand between pylons and schools of yellow-eye mullet and salmon move through the channel edge.

The bottom is a mix of coarse sand, shell and old jetty debris that turns up bottles and lost fishing gear. Newhaven is generally regarded as the poorer relation of San Remo Jetty, 300 m across the water, because the visibility is usually lower and the channel edge is more exposed to the main stream. Its value is that it gives a second option on the same slack, and it sits next to the island's main boat ramp so it is a convenient warm-up or afternoon dive for boat divers coming back in from Cape Woolamai.

This is a dive for experienced divers who already understand tidal timing; there is no margin for a late entry, and a diver caught in the ebb will be carried south under the bridge and out towards the entrance bar.

Cross the Phillip Island bridge from San Remo and take the first right into Forrest Avenue, then Beach Crescent, which ends at the jetty and the Newhaven boat ramp (about 2 minutes' drive from the bridge, 1.5 hours from Melbourne via the M420/Bass Highway). Park in the sealed car park beside the ramp and jetty; it is a 30–60 m carry to the water. Enter from the small beach on the south side of the jetty shed and swim out along the pylons, or use the fishing landing at slack water.

The inner pylons dry at low tide, so plan on the last hour of the flood. Exit back to the same beach before the ebb starts to run.

This is a tidal site, not a swell site. Tidal streams through The Narrows reach 5–6 knots, so the dive is only possible in the 15–20 minute slack at the end of the incoming (flood) tide; use the WillyWeather/BoM Newhaven tide tables and be in the water 10 minutes before predicted high water. Neap tides give a longer, gentler window than springs.

Wind has little effect inside the jetty, but a strong southerly or south-westerly pushes chop and weed into the Narrows and visibility drops after heavy rain when Bass River run-off discolours the eastern arm. Visibility is generally poorer than the neighbouring San Remo Jetty. Diveable year-round; winter often gives the clearest water.

Enter from the beach south of the shed about 10 minutes before slack high water and finn out under the jetty, staying inside the pylon line. Work the outer pylons and the edge of the 10 m channel first while the water is still, then move back towards shore as the ebb begins to pick up. Keep the pylons between you and the channel; do not stray into the fairway, which is used by the fishing fleet.

When the current turns, surface inside the pylons and walk out on the beach. Fly a dive flag throughout.

No dive shop or dedicated dive charter is based on Phillip Island. Sites are dived by Melbourne clubs (VSAG, Melbourne University Underwater Club, Frankston/Peninsula clubs) and private boats launched at Newhaven or Rhyll; Mornington Peninsula shops (Dive Victoria Group, Portsea; The Scuba Doctor, Rye) run occasional Phillip Island days. Ocean Adventures Phillip Island (Cowes) runs seal-snorkel tours only.