Sno Bommie is Scuba IQ's name for a lazy drift dive along the inner slope of North Opal Reef, a site they describe as popular for private charters, with sharks and plenty of action. The inner slope of North Opal faces the lagoon side of the crescent and is sheltered from the prevailing south-easterly swell, which makes it a comfortable place to drift. When the tide runs along the slope it carries divers past a sequence of coral heads, gullies and sand patches, with the bommie itself acting as a focal point where fish congregate.

Reef sharks – whitetips and grey reef sharks – cruise along the slope, and schooling fish such as fusiliers, trevally and snapper gather around the bommie in the flow. The drift format means minimal finning. Divers settle into a comfortable depth, usually 12–15 m, and let the current carry them along, adjusting position with small movements.

The guide carries a surface marker buoy, and the tender tracks the group for pick-up. It suits divers comfortable with drift procedures; on slack water the site can be dived as a gentle out-and-back instead. Scuba IQ does not publish a depth range; most groups work between about 5 and 18 m.

Visibility on Opal typically ranges from 15 to 30 m, and North Opal is known for clear water. Sno Bommie is a good choice for divers who want a relaxed drift with a good chance of sharks. It is frequently requested by private charter groups, who can time the dive to the tide.

Opal is a low-impact reef visited only by medium-sized boats, so even on busy days it rarely feels crowded.

Boats to Opal Reef leave Crystalbrook Superyacht Marina on Wharf Street, Port Douglas; Calypso Reef Cruises checks in around 8:15 am for a 9:00 am departure and returns about 4:30 pm, and Wavelength and Scuba IQ/Blue Dive leave around 8:00 am. Park in the marina car park or on surrounding streets (free all-day parking along Wharf/Dixie streets), or use the operators' courtesy pick-ups from Port Douglas and the northern beaches. Opal is about 60 km north-east of Port Douglas; the crossing takes 80–90 minutes, part of it threading through the protected Tongue Reef maze.

Divers gear up on board and enter by giant stride at a mooring; on Calypso some sites are reached by tender from the main vessel. The skipper chooses three sites on the day depending on wind and tide.

Opal is a crescent-shaped outer reef near the continental shelf edge. Its shape gives some shelter from the south-east trades that blow from about April to September, so several moorings (Bashful, Sno, Blue Buoy) stay diveable in 15–20 knots, but a 25-knot-plus trade wind makes the crossing rough and operators may cancel. Exposed sites on the seaward face and in the channels between North, Middle and South Opal are dived only in light winds and suitable tides.

October–December is typically calmest with the best visibility; the wet season (December–April) brings northerlies, storms, cyclone risk and marine stingers (November–May). Tidal currents run through the gaps between the Opal reef sections and around bommies, strongest on spring tides – channel and bommie sites are timed for neaps or slack water.

Drop in with the guide up-current of the bommie, descend to 12–15 m on the inner slope and drift slowly along it with the reef on one shoulder, pausing in the lee of the bommie to watch sharks. Ascend as a group near the end of the drift for a tender pick-up, doing the safety stop mid-water.

Calypso Reef Cruises – daily Opal trips (3 dives/snorkel sites); Wavelength Reef Cruises – snorkel-only daily trips to exclusive Opal moorings; Scuba IQ / Blue Dive and Tech Dive Academy – small-group dive days several times a week; private charters.