Marmion Marine Park Snorkelling: Boyinaboat Reef, Mettams, Little Island

Why Hillarys Works As A Snorkelling Base

Marmion Marine Park was declared in 1987 as the first marine park in Western Australia. It covers around 10,500 hectares of ocean from Trigg Island in the south to Burns Beach in the north, and Hillarys Boat Harbour sits close to its centre. The Whadjuk people are acknowledged as the traditional owners of the park.

What makes it good for snorkelling is the geology. Limestone reefs run parallel to the coast, creating ledges, platforms and small caves close to shore. The inshore reefs break up the swell, which is why places such as Mettams Pool can feel like a natural swimming pool on a calm morning while the open beach nearby has waves.

The park is also busy with larger wildlife. Australian sea lions and bottlenose dolphins live in these waters, and humpback whales pass through on their southern migration between September and November. You are unlikely to see a whale from a snorkel mask, but a spring morning on the water can deliver a fin, a spout or a sea lion surfacing near the harbour.

When To Snorkel: Spring Water Temperatures And The Morning Rule

Late September into November is the start of the snorkelling season rather than the peak. Published averages for Perth put the sea at about 18.7°C in October, ranging from around 17°C to 20.4°C, and about 19.4°C in November, ranging from around 17.9°C to 21°C. That is refreshing for a quick dip and cold for a 45-minute snorkel, so most adults will be more comfortable in a wetsuit or at least a thick rash vest, and children feel the cold faster still.

The bigger factor is time of day. Perth's afternoon sea breeze is famous for a reason. RAC's snorkelling guide notes that the best time to snorkel around Perth is usually early in the day before the sea breeze blows in and reduces visibility. In practice that means aiming to be in the water somewhere between first light and mid-morning, and treating afternoons as beach, pool and lunch time.

Snorkel guides for Mettams Pool also suggest the change of tide or a smaller tide gives the calmest water. If you only have one morning, choose the calmest forecast day of your stay.

How To Read The Conditions Before You Commit

Local shore divers look for three things: small swell, a short swell period and offshore (easterly) winds. One experienced Perth dive guide describes ideal conditions at Boyinaboat Reef as a one-metre swell, low easterly winds and a swell period under about 11.5 seconds, and advises against diving there with swell above 1.5 metres or with southerly or westerly winds. Calm weather on the days before your snorkel also helps, because it lets the water settle and visibility improve.

The Department of Biodiversity, Conservation and Attractions (DBCA) is blunt about the risk: scuba diving and snorkelling have claimed lives in the park, and swimming into caverns and under ledges can be hazardous. Check the daily conditions, stay out of caves and overhangs, and keep your group within sight of each other.

Mettams Pool: The Easy First Snorkel

RAC calls the sheltered waters of Mettams Pool a perfect snorkelling destination, and it is the natural first stop for beginners. The City of Stirling describes it as a natural rock pool protected by a surrounding reef, on West Coast Drive between Lynn Street and Hamersley Street in North Beach, just north of Trigg Beach. It is a short drive south of Hillarys along the coast.

RAC describes the pool as less than two metres deep and suitable for beginners and families, while snorkel guides put the depth across the wider area at around one to four metres. DBCA's own summary is simple: you literally walk in off the beach. Entry is over sand with some rock around it, so reef shoes or old sneakers help, and children should be watched closely where the rock meets the water.

Expect small reef fish rather than big animals. Snorkel guides list toadfish, striped grunter, whiting, damselfish, monocle bream, gold-lined bream, banded sweep, western scalyfin and many wrasse species, along with schools of bream and herring on a good day.

The catch is popularity. Mettams Pool is small and busy, and the car park is reported to fill early on fine days, often by about 7.30am. Arrive early, bring everything you need in one trip, and have a backup plan such as a walk along the coastal path if parking is full. The City of Joondalup's marine park map also marks a disabled access ramp at Mettams Pool, and the City of Stirling lists toilets on site.

Boyinaboat Reef: Hillarys' Own Sanctuary Reef

Boyinaboat Reef is the reason serious snorkellers and divers come to Hillarys. DBCA calls it one of Perth's most popular dive sites. It sits at the southern end of an inshore reef chain in about six metres of water, and official sources place it between roughly 75 and 100 metres from the Hillarys Boat Harbour seawall.

The reef is a sanctuary (no-take) zone and the surrounding area is closed to vessels. It also has an underwater nature trail of sunken plaques describing the local marine life, though local divers note some are now heavily encrusted and hard to read.

What you will see depends on visibility, but reports from divers describe sponges, tube worms, bryozoans, lace corals and ascidians on the limestone, with leatherjackets, cods, pike, morwong, drummers, old wives and boxfish around the ledges. Dive operators also mention blue gropers, crayfish and Port Jackson sharks in the wider area. DBCA's own site notes schools of garfish in the shallow water over the reef top.

RAC is clear that accessing Boyinaboat can be difficult and recommends it for experienced snorkellers. Six metres is too deep for most people to reach the bottom comfortably, and there is a swim across open water to get there. It is a rewarding snorkel for fit adults and confident teenagers on a calm day, not a first outing for young children.

Getting To Boyinaboat Safely

There is no pontoon or marked beach entry at the reef, so plan the swim before you start. One long-running Perth shore-diving guide describes two approaches. The first involves a walk of more than 300 metres along the concrete path to the T-junction on the harbour wall, then a careful climb down six to eight metres of steep rocks to the water. The second uses a small set of steps cut into the groyne near the car park behind the Aquarium of Western Australia (AQWA), followed by a long surface swim of about 400 metres to the reef.

Both options involve rocks, distance and boats nearby, so a few habits make a big difference:

If that sounds like more than your group wants, that is a reasonable answer. DBCA notes that private dive charters and diving instruction operate from the area for most of the year, and a guided session removes most of the navigation worry.

Little Island By Kayak: Sea Lions And A Snorkel Trail

Little Island is a small, uninhabited sand and limestone island just off Hillarys. The waters around it are a marine sanctuary, and it is one of the places in the Perth area where visitors can see Australian sea lions resting on land. The City of Joondalup's marine park map also marks a Little Island Underwater Nature Trail through reef tops, seagrass, kelp and sargassum, with about 30 minutes suggested to complete it.

Trails WA lists a Little Island Kayak Trail as a five-kilometre loop graded easy, taking one to three hours, starting off the beach on the north side of Hillarys Boat Harbour. There is an accessible kayak launching platform near the boat ramps inside the harbour. The trail notes say the best conditions are from September to April, with mornings usually best before the wind comes in.

The rules are important. Beaching kayaks on the island is not allowed and walking on the beach is discouraged: the island is left for the birds and sea lions. Trails WA suggests taking a small anchor if you want to snorkel, with good snorkelling to the west and south of the island. Give sea lions plenty of space in the water and on land, and never try to feed or approach them.

Paddlers need to watch for ferry and powerboat traffic near the marina entrance and follow the Department of Transport's safety guidelines for paddle craft at sea. It suits experienced paddlers rather than a first kayak trip.

What You Might See Under The Water

The Marmion reefs are temperate rather than tropical, so the colour comes from sponges, seaweeds and fish rather than big coral gardens. On a clear morning that still makes for a busy snorkel.

If the sea is too rough to get in, the Aquarium of Western Australia at Hillarys Boat Harbour shows many of the same local species behind glass, which is a useful preview for first-timers before a calm morning arrives.

Sanctuary Zones, Fishing And Spearfishing Rules

Most of Marmion Marine Park is open for recreational fishing, but not all of it. Boyinaboat Reef and the waters around Little Island are sanctuary zones, which means nothing may be taken: no fishing, no collecting shells or animals and no spearfishing. The City of Joondalup's marine park guide shows three sanctuary zones, including Whitfords Nodes beside Hillarys.

The same map marks areas where spearfishing is banned within 1,800 metres of shore. If anyone in the group plans to fish or spear, DBCA's advice is to check the latest size, season and bag limits with the state fisheries department before heading out, because rules change and seasonal closures apply to some species.

For snorkellers, the simplest approach is to look and not touch. Avoid standing on reef, keep fins off the bottom in shallow water and take any rubbish home. The sanctuary rules are the reason the fish are so relaxed around people here.

Sharks, Surf Patrols And Staying Safe

Shark encounters are rare, but they are part of swimming anywhere on the Perth coast, and checking before you go is a normal local habit. The SharkSmart WA website and app show the latest reported sightings and tagged shark detections on an activity map. At beaches without a patrol, SharkSmart advises checking current activity yourself before entering the water.

The metropolitan surveillance helicopter covers the coast from Mandurah to Yanchep, plus Rottnest Island. For this season SharkSmart lists daily flights from 26 September 2026 to 30 April 2027, after weekend flights in September.

Volunteer surf lifesaving patrols return to Perth beaches in early spring. As a guide to timing, the Trigg Island Surf Life Saving Club's 2025-26 roster ran from Saturday 4 October 2025 to Sunday 29 March 2026, with October weekend patrols from 9am to 12.30pm and 12.30pm to 4pm. Mullaloo Surf Life Saving Club has published its 2026-27 roster for members. Check the club or Surf Life Saving WA for this season's exact dates and hours before relying on a patrol.

Snorkel spots are usually outside the flags, so for snorkelling the buddy system, a bright cap and conservative conditions are your main protection.

Gear That Makes Spring Snorkelling Comfortable

Good gear matters more in cool water. A leaking mask or a cold child ends the session early.

Mask and snorkel: Test the fit by holding the mask to the face without the strap and breathing in gently through the nose. If it stays put, it should seal in the water.

Wetsuit or thermal top: With October water averaging under 19°C, a spring suit or full wetsuit keeps most people comfortable for longer. Children lose heat quickly, so keep their sessions short and have a towel and warm jumper ready.

Fins and reef shoes: Fins are essential for the Boyinaboat swim. At Mettams, reef shoes or old sneakers help with the rocky edges.

Visibility: A bright swim cap or towed float makes snorkellers easier to see from the shore and from boats. Scuba divers must fly a dive flag.

Sun protection: Spring sun on the water is strong. A long-sleeved rash vest protects backs and shoulders better than sunscreen alone during a long face-down session.

Snorkelling With Kids And First-Timers

Children usually enjoy snorkelling most when the first attempt is short, shallow and successful. Start where they can stand, let them breathe through the snorkel with their face in the water before swimming anywhere, and come out before they get cold rather than after.

Mettams Pool is the natural first choice because of its shallow, reef-protected water. The sheltered water at Marina Beach inside Hillarys Boat Harbour can be useful for a quick practice with masks on a day when the open coast is too lively. Check local signage for any swimming restrictions near boat ramps and moorings.

Keep one adult out of the water as a spotter where possible, and never push nervous swimmers towards the deeper reefs.

A Plan For The Non-Snorkellers In The Group

In most groups not everyone wants to put their face in cold water at 7am. Hillarys makes it easy to split up and meet again.

While the snorkellers are at Boyinaboat, others can walk the harbour, grab a coffee and settle at Hillarys Boat Harbour, which has two retail and dining precincts, Sorrento Quay and Hillarys Boardwalk. The Boardwalk lists waterside dining including the Breakwater Tavern and a Putt Putt by the Sea mini golf course for families. AQWA sits within the harbour too, along with cruises, fishing charters and the daily Rottnest Island ferry.

At Mettams Pool, non-swimmers can walk the coastal path or head for breakfast while the snorkellers finish. Agree on a meeting time and place before splitting up.

Why Sant's Beach Retreat Suits A Hillarys Snorkel Stay

Snorkelling in spring is an early-morning activity, so where you sleep matters. Sant's Beach Retreat in Hillarys puts the harbour, Boyinaboat Reef and the Little Island kayak launch a short trip from the front door, and Mettams Pool is a short drive south along the coast. That makes a dawn session and a return for breakfast practical rather than a long drive in the dark.

Current WTP listing information shows five bedrooms, three bathrooms and space for up to 10 guests across a split-level home. For families and groups sharing gear, three bathrooms help after a salty morning, and guest reviews mention a separate large-capacity washer and dryer, which is handy for towels and rash vests.

The home has a private fenced swimming pool, which gives first-timers a calm place to try on masks and practise breathing through a snorkel before they meet the ocean. When the sea breeze arrives, the covered outdoor dining, BBQ, outdoor fireplace and fire pit turn the afternoon into an easy time at home.

There is a full kitchen for cooking a proper breakfast after an early swim, several living areas and a movie theatre room for windy afternoons, and a balcony with outdoor seating and a coastal outlook above the backyard. The listing also shows the home as pet-friendly. Check the live listing for the latest details, and note that one guest review mentions stairs, with three bedrooms and the main facilities on the middle level.

Who This Stay Suits And How A Group Can Use It

This style of trip suits families with school-age children who want a beach holiday with a bit of adventure, and groups of friends or extended families where some people want the reef and others want the pool, the harbour and a long lunch.

A practical rhythm for a group of eight to ten looks like this: the keen snorkellers leave at first light, the rest of the house wakes slowly, and everyone meets back for a cooked breakfast. The middle of the day goes to the harbour, AQWA or the pool, and the evening is BBQ and fire pit time while wetsuits dry.

The backyard play space with an in-ground trampoline, climbing frame and slide gives younger children something to do while older ones go out on the water. The dedicated workspace and fast Wi-Fi also help if one adult needs to work a few hours while the others snorkel.

A Three-Morning Hillarys Snorkel Itinerary

Morning One: Mettams Pool To Build Confidence

Check the forecast the night before and aim to arrive at Mettams early. Keep the first session short, let everyone test their gear, and note who is comfortable in deeper water. Walk part of the coastal path afterwards and head back for breakfast before the sea breeze.

Morning Two: Boyinaboat Reef For The Confident Swimmers

If the swell is small and the wind is easterly, take the strong swimmers to Boyinaboat. Go as a pair or group, mark your exit, swim with a bright cap or float and keep well clear of the harbour entrance. The rest of the group can take a harbour walk, coffee and mini golf on the Boardwalk.

Morning Three: Little Island Or A Rest Day

Experienced paddlers can use a calm morning for the Little Island kayak loop, or book a guided dive or snorkel charter. If the wind is up, make it a pool, AQWA and long-lunch day instead. Nothing on the reef is going anywhere.

What To Pack For A Spring Snorkel Trip To Hillarys

Bring masks, snorkels and fins for each swimmer if you have them, plus wetsuits or thermal tops for the cooler spring water. Reef shoes, a bright swim cap or towed float and a dry bag for keys and phones all make the morning easier.

Pack warm clothes for after the swim: a hooded towel or dry robe, a jumper and a thermos can turn a chilly exit into a pleasant breakfast on the beach. Add hats, sunscreen, rash vests and water bottles for the rest of the day.

Before You Leave Home: Your Hillarys Snorkel Check

Plan Your Spring Snorkel Stay In Hillarys

Hillarys gives visitors something few Perth suburbs can: a protected marine park at the end of the street, with reef fish in the morning and harbour dining by lunchtime. Pick the calm mornings, start easy and let the rest of the stay be about the pool, the fire pit and the sunset.

See dates, photos and the latest details for Sant's Beach Retreat, or browse and book WTP holiday homes. For more local ideas, read the other WTP holiday home guides.