Lighthouse Bommies is the most famous dive at Lady Elliot Island and the one most visitors come for. Off the island's western side, near the historic lighthouse, a group of small bommies covered in coral and sponges rises from sand at about 14 m. The resort calls it a virtual truck-stop for manta rays, and whole dives can be spent watching the activity around this one site.

The bommies host cleaner wrasse that service reef manta rays, which hover and loop over the coral heads, sometimes performing acrobatic displays. Lady Elliot is known for its resident manta population, including individuals recognised over decades, and the peak season is roughly May to August, although mantas are seen in most months. Around the bommies, garden eels rise from the sand, cowtail rays and shovelnose rays rest nearby, and schools of glassfish shelter in the coral.

Green turtles feed in the soft coral beds, and trevally, batfish, sweetlips, coral trout and groper are common. Leopard sharks are also recorded on the sand. The site is shallow, sheltered in the prevailing south-easterlies and very easy, so it suits new divers and snorkellers as well as photographers.

The key to good encounters is behaviour: stay low, keep still, avoid blocking the cleaning stations and let the mantas approach. Lighthouse Bommies is also a gateway to neighbouring sites: Forty Five, a single bommie on a mooring angled south-west of the Lighthouse, and the Scattered Bommies between here and the Severance wreck, both of which share the manta traffic.

Lady Elliot Island is the southernmost coral cay of the Great Barrier Reef, about 80 km north-east of Bundaberg, and is reached only by the resort's light aircraft from Bundaberg, Hervey Bay, Brisbane (Redcliffe) or the Gold Coast (baggage limit about 15-16 kg, extra dive-gear weight bookable). From the airstrip, walk to the resort dive shop; boats are launched from the western beach or the lighthouse side and all dive sites are 10 minutes or less by boat. Lighthouse Bommies is off the western side near the lighthouse, a few minutes by boat, dived from a mooring.

The island has a western (lee) side and an eastern (windward) side. Under the prevailing south-east trades the western sites (Lighthouse Bommies, Coral Gardens, the Severance) are sheltered and dived most days; the eastern wall sites (Blowhole, Tubes, Hiro's Cave) need light winds or a westerly/northerly. Swell over about 2 m from the south-east closes the eastern side, and strong northerlies (spring/summer) make the west choppy.

Tidal range is about 2-3 m; currents are strongest at the southern tip. Summer brings warmer water but more plankton and occasional cyclones (November-April). Western sites are the default in the prevailing south-easterlies; they become choppy in strong northerlies or westerlies.

Descend the mooring to the sand at about 14 m beside the bommies and settle on the sand at a respectful distance from the cleaning stations. Wait for mantas to arrive and circle, then move slowly between bommies looking for garden eels, rays and turtles, and ascend the mooring for the safety stop.

Lady Elliot Island Eco Resort's PADI dive shop is the only operator: guided boat dives twice daily (early morning and afternoon, bookings open the day before), plus courses; boat rides are 10 minutes or less and all sites are moored. Day-trip packages from Bundaberg, Hervey Bay and the Gold Coast include diving. The resort does not offer shore dives.

Lighthouse Bommies is dived most days in manta season.