New Seagull is an exposed Opal Reef site with open ocean exposure and a buttress reef structure, according to Wavelength Reef Cruises. The operator visits it seasonally, during calmer periods in the wet season when the trade winds ease. Buttress reefs – often called spur-and-groove – form on the seaward faces of outer reefs, where wave energy shapes the coral into ridges (spurs) separated by sand or rubble channels (grooves).

The spurs are covered in robust corals adapted to wave action, and the grooves channel water and sediment. The result is a dramatic landscape of coral ridges running out towards deeper water. The exposure to open ocean means clear water and a chance of pelagic fish – trevally, mackerel and reef sharks – along with reef fish sheltering among the buttresses.

The coral on the spurs tends to be robust, with massive and encrusting forms. Because of its exposure, New Seagull can be visited only in calm conditions; during the south-east trade season it is usually too rough. No depth figures are published; the snorkel area is on the upper spurs, with deeper water beyond.

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.

New Seagull faces the open ocean and is exposed to the south-east trade winds and swell that dominate April–September; it is visited seasonally, mainly during calm spells in the wet season when the trades drop out. Any significant swell or wind over about 15 knots from the south-east rules it out. Wet-season visits bring marine stingers (November–May), storms and cyclone risk.

On a calm day, snorkel (or dive, on charter) along the buttresses and the grooves between them, staying out of any surge near the crest and watching the blue for pelagic fish.

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).