Meet the site
The Boomer is a small rocky dome in Mary Ann Bay, rated 5 out of 10 by the Marine Life Network guide as an easy, relaxing dive in calm weather. It breaks in all but the calmest conditions (hence the name) and offers some shelter from easterlies, with shallow depths of 3-9 m and an unusual variety of short green and brown algae. Wrasse, magpie perch and leatherjackets shelter in the crevices, and there are small abalone. It becomes murky in any swell. The Leven Scuba Club includes it among the Rocky Cape sites. Local divers typically combine two or three Rocky Cape and Sisters Island sites in a day, choosing the side of the cape that suits the wind and the state of the tide.
The Rocky Cape and Sisters Island area is, in the Leven Scuba Club's words, the best collection of dive sites on the north-west coast. The quartzite of Rocky Cape - some of the oldest rock in Tasmania - forms gutters, ledges, caves and bommies, and the tidal flow along Bass Strait keeps sponges, gorgonians, sea pens and bryozoans well fed. Michael McFadyen, diving here in February 2008, recorded 18-19 °C water and 20-25 m visibility, figures that surprise divers used to the east coast.
Rocky Cape National Park also protects Aboriginal cave sites and coastal heath above the water, and a Parks Pass is required for vehicles. The nearest hyperbaric chamber is the Royal Hobart Hospital, about four hours' drive away, so conservative profiles and oxygen on the boat are essential.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
The Boomer (Mary Ann Bay) is recorded as Reef in Tasmania North & North-West. The listed access is boat. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is The Boomer (Mary Ann Bay) suitable for my certification?
The record lists Open Water. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book The Boomer (Mary Ann Bay) through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Wrasse, magpie perch, leatherjackets, small abalone, short green and brown algae
Location
A small rocky dome in Mary Ann Bay off the western rocky point of Rocky Cape, which breaks in all but the calmest weather.
Facilities nearby
Rocky Cape National Park: day-use areas, toilets and picnic facilities at Mary Ann Bay/western end and near the lighthouse road; no shops. Sisters Beach and Boat Harbour have small general stores; Wynyard for all services. No confirmed air fills on the coast - Launceston is the reliable option.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
marinelife.org.aulevenscubaclub.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.