Rayban is a shallow Opal Reef snorkel site visited by Wavelength Reef Cruises. The operator describes prolific coral cover with clownfish, schools of damselfish and a high density of fish, including parrotfish and angelfish. The appeal is simple: a shallow reef where healthy coral grows close to the surface and fish are abundant.

Snorkellers can float over coral heads just a metre or two below, watching clownfish nestle in their anemones, damselfish hover in clouds above branching coral, parrotfish graze on the reef with audible crunching, and angelfish drift between the coral heads. Look for giant clams, sea cucumbers and blue starfish on the reef and sand. Because it is shallow and generally sheltered, Rayban suits snorkellers of all ages and abilities, including families and first-timers.

The shallow depth makes colours vivid, especially on sunny days, and there is plenty to see without diving down. The site is not documented as a scuba site by Wavelength, and no depth figures are published. Divers visiting on a private charter would find it a shallow reef best suited to a relaxed, low-depth dive or a final dive of the day.

Wavelength is a snorkel-only operator that runs a single fast catamaran to its own exclusive moorings, carrying marine biologists who guide snorkel tours and give reef talks; the skipper picks three of the company's sites each day according to wind and tide, so no single site can be guaranteed. Scuba divers who want to see the site underwater at depth would need to charter a small-group dive boat, and the site name may not be used by other operators.

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.

Snorkel from the boat over the shallow coral with the marine-biologist guide, keeping a little above the coral heads, and circle back to the boat along the reef edge.

Wavelength Reef Cruises – snorkel-only full-day trips (max ~40 guests, marine-biologist guides) visiting three rotating Opal/Tongue/St Crispin sites daily; the site name is Wavelength's own. Scuba divers would need a private charter (e.g. Scuba IQ / Blue Dive, Tech Dive Academy).