Entrance Bommies sits at the mouth of Lady Musgrave's lagoon, where the tide pours in and out through the reef. The site is made up of large isolated and scattered bommies, many decorated with plate corals and foliose (lettuce-leaf) corals, whose thin, plate-like structures resemble the open petals of a flower. Depths are 14-18 m and visibility typically 12-30 m.

Because of the tidal flow, the site is dived as a drift, with divers carried from bommie to bommie. The moving water attracts sharks (whitetip, blacktip and grey reef), rays (eagle, sting and bull rays), giant trevally and baitfish, and manta rays pass through. Clownfish live in anemones on the bommies, and humpback whales are possible between July and October.

Marine life writers note that the lagoon mouth is a colourful spot also used for snorkelling and glass-bottom boat viewing at its shallow edges, with occasional reef sharks, stingrays and sea snakes. The dive is led by a divemaster from the tender Underworld with free descents and ascents. It suits Open Water divers with recent experience and comfort in current, and it is often dived as the second outer-reef dive of a day trip.

The contrast between the delicate foliose corals and the pelagic action makes Entrance Bommies one of the more photogenic Lady Musgrave sites. Boat traffic in the entrance channel is a consideration, so divers must stay with the group and surface under the guide's marker. Private yachts use the same entrance to reach the lagoon anchorage, which is one reason the operator keeps divers tightly grouped and surfacing together.

Lady Musgrave Island is about 96 km north-east of Bundaberg and 59 km east of the Town of 1770. Lady Musgrave Experience departs 15-17 Marina Drive, Burnett Heads (15 minutes' drive from Bundaberg; parking at the marina) at about 7:30 am for a roughly 2-hour crossing to its pontoon in the lagoon; 1770 Reef Eco Tours leaves the 1770 Marina (free parking beside the marina cafe) for a roughly 90-minute run. Private vessels anchor inside the lagoon via the marked entrance channel through the reef.

Entrance Bommies lies at the lagoon entrance, a few minutes from the pontoon by the dive tender Underworld.

The lagoon itself is diveable in almost any weather, but the crossing is open ocean and tours are cancelled when south-easterly trade winds exceed about 25 knots or the swell is over 2.5 m. Outer-reef drift sites are chosen by wind and tide: the northern and western edges shelter from south-easterlies, the southern ledges need light winds or northerlies. Currents strengthen on spring tides and the outer sites are run as drifts on either the flood or ebb.

Cyclone season is November-April; summer storms and plankton reduce visibility. Calmest seas are often September-November and March-April. Water flows in and out of the lagoon through the entrance with the tide, so the site is dived as a drift; the entrance channel also carries boat traffic.

Giant-stride from the tender Underworld at the up-current end, make a free descent with the divemaster to the reef edge and drift with the current along the wall or bommie line at the depth set in the briefing. Stay together behind the guide, check under overhangs and in the blue as you go, and ascend with the group for a free-ascent safety stop under the guide's SMB; the tender follows and collects the group.

Lady Musgrave Experience runs daily tours from Burnett Heads (Bundaberg) aboard Reef Empress to its Lady Musgrave HQ pontoon, with certified divers transferring to the dive tender Underworld for the 'Adventure Outer Reef Double Dive'; overnight stays on the pontoon allow extra and night dives. 1770 Reef Eco Tours also dives Lady Musgrave from the Town of 1770.