Jimmies Island is a small island inside Batemans Bay, and it is one of the sites Beneath the Bay uses for divers of all levels. The Marine Life Network lists Jimmy's Island at 6–18 m inside the Batemans Bay Marine Park and describes it as well known for good fish life, including sea dragons, with gutters, swim-throughs and overhangs. A bommie near the island, called Jimmy's Secret, has similar gutters, swim-throughs and overhangs and rich fish life. NSW DPIRD also lists Jimmies Island among the grey nurse shark areas where special rules apply.

The island's reef is mostly rock and boulders with kelp and crayweed on the upper surfaces and sponges and sea squirts in the gutters. The gutters and swim-throughs are short and open, suitable for newer divers with good buoyancy. Weedy sea dragons are found over the kelp. Fish include blue groper, red morwong, sweep, yellowtail, bream and leatherjackets, with wobbegongs and eastern blue devilfish under the ledges and octopus in the rocks. Rays and flathead are on the sand.

The site suits Open Water divers, training dives and relaxed fun dives. Its position inside the bay means it can be dived when the outer sites are too rough, but it is also where rain runoff reduces visibility first. Published coordinates were not found; ask the operator for the location. Grey nurse shark rules apply around the island. Jimmy's Secret makes a good second dive, since it is close by and has a similar mix of gutters and fish without the crowds.

Boat access only. Beneath the Bay dives Jimmy's Island from the Hanging Rock ramp in Batemans Bay; it is inside the bay and only a short run, typically under 10 minutes. Private boats can use Hanging Rock, Batehaven or Wimbie Beach ramps.

Anchor in sand or rubble clear of the reef, and keep a lookout for the heavy recreational boat traffic in the bay on summer weekends.

Sites inside Batemans Bay get shelter from southerly swell from the southern headlands and islands, so they are diveable on many days. Strong easterly swell wraps into the bay and causes surge, and strong westerly winds make the anchorage choppy. After heavy rain the Clyde River floods the bay with brown water and visibility can fall to a few metres for days.

Jimmies Island is inside the bay and is a reliable option in southerly weather and in moderate seas.

Descend and explore the gutters and overhangs around the island at 8–15 m, passing through the swim-throughs where they are open. Look for sea dragons over the kelp and return to the anchor. On a second dive, try Jimmy's Secret nearby.

Beneath the Bay lists Jimmy's Island as suitable for beginners and experienced divers. The Marine Life Network lists Jimmy's Island and Jimmy's Secret as boat/charter sites.