Ramsbotham Rocks lie off the north-east tip of Great Glennie Island, the closest corner of the Glennie Group to Tidal River, and Scuba Doctor lists them as a 20–30 m wall dive with interesting rock formations and large boulders with caves and swim-throughs, descending to a sandy bottom around 30 m. The site's practical importance is stated in the listing: it is a sheltered spot to dive, especially if there is a south-easterly wind blowing, and since the Prom's diveable days are so often south-easterly-wind days after a change, Ramsbotham Rocks is where a Tidal River-based boat frequently ends up. The dive is entirely in the 20–30 m band, which makes it an Advanced dive despite the shelter: the rocks are giant granite blocks fallen from the island and piled on the sand, leaving caves, tunnels and overhangs between them that a diver can move through, with the boulder tops at about 20 m.

At that depth the kelp is gone and the granite is covered in the Glennie Group's sponge, zoanthid and gorgonian growth, with bryozoans and jewel anemones in the caves, crayfish in the recesses, and the perch, sweep and bullseye schools that gather around isolated structure. Seals from the Glennie haul-outs and the occasional visiting kingfish add movement, and draughtboard sharks and blue devils use the caves. The depth limits bottom time and the site is best on nitrox.

It combines naturally with a shallower second dive on Great Glennie's eastern slopes or a seal snorkel, and it is the Glennie Group's bad-weather option – dived more often than the group's exposed western walls precisely because it is available when they are not.

Boat only. The nearest launch is the Tidal River beach ramp at the western end of Norman Bay (4WD beach launch, key and deposit from the Parks Victoria office; needs several people and calm surf), from which the western islands are 5–12 km. Larger trailer boats launch at Port Welshpool (sealed ramp, Corner Inlet) and run about 50–60 km around South East Point – 1.5–2 hours – or at Sandy Point (Waratah Bay, beach ramp) and run 35–45 km south-east.

Sites are exposed to Bass Strait and require settled weather, a seaworthy boat, radio, and self-sufficiency: there is no rescue or refuelling closer than Port Welshpool. Ramsbotham Rocks are on the near, north-eastern corner of Great Glennie, about 5.5 km and 15–25 minutes from the Tidal River beach launch; anchor in sand off the rocks at 20–25 m. The spot is sheltered in south-easterly winds.

Described by Scuba Doctor as a sheltered spot to dive, especially if there is a south-easterly wind blowing – the north-east tip of the island is in the lee of the whole Glennie Group from the south and east. Exposed to north-westerly through south-westerly winds and to the prevailing swell wrapping round the island. Depth 20–30 m means a clean profile is needed.

Late summer and autumn.

Descend the anchor to the sand at 28–30 m at the base of the rocks, work through the caves and swim-throughs among the large boulders with the island on one shoulder, and ascend gradually along the formation to 20 m as gas is used. Return to the anchor line for the ascent and complete a full safety stop; EAN32 extends the dive usefully.

EAN32 recommended for the 20–30 m profile.

No dive charter operates at Wilsons Promontory. Sites are dived from club and private trailer boats – Dive La Trobe, VSAG, Melbourne University Underwater Club and Dive Victoria Group run occasional camping-and-diving trips – launching at Tidal River (beach launch, permit/key from Parks Victoria), Port Welshpool or Sandy Point. Wilsons Promontory Cruises (Port Welshpool) runs sightseeing cruises to Skull Rock and the islands but no diving.