Open Water Training Dives: What to Expect

The pool is over and you're heading to the ocean. Here's what happens across the four open water dives that turn you from a student into a certified diver.

Why the open water dives are the part you'll remember

Ask any diver about their certification and they will not tell you about a quiz or a regulator-clearing drill. They will tell you about the moment they descended into open water for the first time and looked at a fish that ignored them. That happens on Open Water Dive 1.

The four open water training dives are where everything you learned in theory and practised in the pool comes together in real conditions. They are also a rolling assessment: your instructor is checking that you can use the same skills outside the pool. Once you have finished the four dives and the rest of the course, you are a certified Open Water Diver, qualified on PADI's course to dive with a buddy to 18 metres without an instructor.

The big picture: The pool taught you the mechanics. The four open water dives prove you can do them when there's a current, a thermocline and something interesting swimming past. They are not harder than the pool, but they are different.

What "open water" actually means

"Open water" is the certification agencies' term for a dive site that is not a pool or pool-like confined water: in Australia, nearly always the sea. Depths on the training dives are deliberately limited, on PADI's course and SSI's alike:

- Dives 1 and 2: maximum depth 12 metres. - Dives 3 and 4: maximum depth 18 metres, the limit of an Open Water Diver.

You will do four separate dives, each with its own briefing, skills and debrief. They are usually split across two days, two dives a day: PADI and NAUI allow no more than three training dives in one day.

Where Australian students do their open water dives

Schools pick the site on the day to suit wind and swell, so treat these as likely rather than promised. Some well-known sites are closed, so check yours is open.

- Sydney: shore dives at Shelly Beach in Manly, Camp Cove inside the harbour, Gordons Bay and Clovelly in the eastern suburbs, and Clifton Gardens on Chowder Bay. Bare Island at La Perouse, once a training site, has been closed to all visitors since 24 August 2026 and is not due to reopen until about late 2027. Our Sydney guide has the detail. - Cairns and Port Douglas: after two days of pool and theory in town, schools take students to the outer reef, either on day trips (Divers Den uses Norman, Saxon and Hastings reefs; Quicksilver Dive uses the Agincourt Reefs) or for one or two nights on a liveaboard (Pro Dive Cairns dives Flynn, Thetford, Milln and Pellowe reefs). - Melbourne: Scuba Culture names Rye, Blairgowrie and Flinders piers on the Mornington Peninsula as the popular training sites, and many courses add a boat dive. Portsea Pier has been closed for repairs since 17 August 2026. - Brisbane and the Gold Coast: Wave Break Island in the Broadwater, the Gold Coast Seaway, the Tweed River at Jack Evans Boat Harbour, and boat dives in Moreton Bay or at the Tangalooma Wrecks. - Perth: local beaches chosen on the day, Perth Diving Academy's house reef at Hillarys, and boat dives at Rottnest Island. Mettams Pool at Trigg is a snorkelling and swimming spot, and none of the six Perth schools we checked uses it for scuba training. - Adelaide: shore dives at Port Noarlunga, or boat dives off Glenelg. The water beneath the old Rapid Bay jetty has been a prohibited area since June 2025, and Edithburgh Jetty is closed until mid-2027.

You can browse the SDU dive-site directory to see depth, conditions and skill level for each site, and our guide to where to get scuba certified in Australia compares the cities.

Good to know: Cairns courses are popular because they bundle the reef, transfers and, on liveaboard courses, meals and a bunk into one trip. The trade-off is intensity: four training dives in two days. City courses fit the dives into two or three days, and some Melbourne schools spread them over two weekends.

The day before, and the morning of

The night before your first ocean dive, get a good night's sleep, drink enough water and skip the alcohol: Queensland's dive code says anyone who has drunk alcohol in the eight hours before diving should not dive. DAN notes that your dive profile (depth, time and ascent rate) is the biggest factor in decompression risk, and that hard work and getting cold also matter, so on the day keep your effort low and stay warm.

Your medical questionnaire should already be done. If any answer called for a doctor, you need the doctor's clearance before the open water dives; Queensland law makes that a requirement.

In the morning you'll typically:

1. Arrive at the dive shop, beach or boat at the time your school gives you. 2. Sign in and complete any remaining paperwork. 3. Be issued hire gear that fits: wetsuit, BCD, regulator, weights and tank, and a mask if you don't own one (see Gear You'll Use in Your Course). 4. Receive a site briefing from your instructor: entry and exit points, depth, expected current, hazards, marine life and the planned skills. 5. Do a buddy check (PADI calls it the predive safety check) with your buddy and instructor. 6. Enter the water, either by giant stride from a boat or by walking in from a beach or jetty steps.

A full dive day is longer than people expect: Abyss in Sydney runs its course days from about 7:45 am to 5 pm. It is more tiring than people expect, too.

Open Water Dive 1, your first ocean dive

Maximum depth: 12 metres. The instructor's job on this dive is to get you comfortable in open water before asking you to demonstrate anything difficult. On PADI's course, Dive 1 includes:

- A weight check at the surface, then a controlled descent down a line or a gently sloping bottom, equalising early and often. - A trim check. - Clearing a partly flooded mask, the same skill as the pool, in salt water. - Regulator recovery and clearing, retrieving a regulator that has come out of your mouth and clearing the water from it. - Exploring the dive site with your buddy close enough to touch within two seconds. - Signalling your remaining air to your buddy and instructor. - A slow ascent. PADI's standards set a maximum of 18 metres a minute, and SSI says never exceed 10 metres a minute.

What you'll notice in the moment: the salt taste in your regulator, the colours fading as you go deeper (the US Navy notes red light is filtered out first), the sound of your own breathing, and how strange it feels to be weightless with fish behaving as if you aren't there.

What surprises new divers most: how casual the fish are. They have seen plenty of bubbling humans before you and consider you scenery.

Open Water Dive 2, sharing air

Maximum depth: 12 metres. This is the dive where you practise responses to things that could go wrong, in a controlled way, so you would handle them if they ever did. On PADI's course, Dive 2 includes:

- Planning the dive with your buddy, including air supply, time limits and what to do if you get separated. - Inflating your BCD by mouth at the surface. - Becoming neutrally buoyant using the BCD's inflator. - Clearing a fully flooded mask. - Sharing air: both roles, giving and receiving air from an alternate air source (the spare second stage, or "octopus"), then ascending together while sharing air. - A safety stop if it is practical.

Some skills, called flexible skills on PADI's course, can be done on any of the four dives at your instructor's choice. At the surface these include releasing a cramp, towing a "tired" buddy 25 metres, deploying a surface marker, a 50-metre compass swim, removing and replacing your weights and scuba unit, and an emergency weight drop. Underwater on Dive 2, 3 or 4 you also do a compass navigation swim and the controlled emergency swimming ascent (CESA): starting from 6 to 9 metres, you swim slowly up while breathing out continuously and making a sound (a long "aaah" works), with your instructor holding you and a line so the ascent can be stopped at any moment.

Almost every student finds the CESA the strangest skill. It feels counterintuitive to swim up while breathing out. Practising it under control is exactly why it's there: DAN's order of preference is a normal ascent if you still have air, then your buddy's air, and an emergency ascent alone only if neither is possible.

Open Water Dive 3, depth and buoyancy

Maximum depth: 18 metres. This is where the depth limit moves to the full Open Water range. On PADI's course, Dive 3 includes:

- Descending with a visual reference to no more than 18 metres. - Hovering after inflating your BCD by mouth: holding a position in mid-water without kicking. - Removing, replacing and clearing your mask underwater. Less awful than it sounds: the regulator still works without the mask. - Keeping track of your air and signalling it at the intervals you agreed. - A safety stop if it is practical.

By Dive 3 most students are noticeably more comfortable in the water and start looking around rather than staring at their gauges.

Open Water Dive 4, the qualifying dive

Maximum depth: 18 metres. This is the dive where your instructor effectively says, "show me you can do this." It feels closer to a real recreational dive than any of the previous three. On PADI's course, you:

- Plan the dive as a buddy team. - Descend without a visual reference to no more than 18 metres. - Explore the site with your buddy, avoiding contact with the bottom and anything living on it. - Signal when to turn the dive and when to ascend, based on your air or time. - Make a slow ascent and a safety stop. PADI's guidance is about three minutes at around 5 metres.

Back on the boat or beach, your instructor signs your training record.

What is different from the pool

The skills are the same. Five things change:

1. Visibility is variable. Pro Dive puts Sydney's Shelly Beach at 3 to 15 metres, usually clearer in winter. Plan for the lower end. 2. You are colder. The US Navy notes a diver in just a swimsuit starts to chill below about 21°C, and Sydney's water is about 17 to 21°C from June to October. Multi-dive days compound the cold, which is why Sydney schools lend 5 mm or 7 mm wetsuits. 3. There is current and surge. Even a gentle current asks more of your finning than the pool, and surge near the surface at shallow sites can rock you sideways. 4. Equalisation is harder when you're congested. A blocked nose that's tolerable on land can stop your descent. Don't dive with a head cold, and see our equalisation guide. 5. There are things to look at. Distraction is the big difference. Keep track of your air, depth and buddy even when there's a turtle going past.

Common difficulties and how to handle them

- Seasickness on the boat. DAN suggests staying in the part of the boat that moves least, usually the middle, keeping low and looking just above the horizon. If you are thinking about medication, ask a doctor or pharmacist well before the trip: DAN warns that common seasickness tablets can cause drowsiness, which can impair your diving. - Trouble equalising. Descend slowly and equalise gently and often, before you feel pressure. If an ear won't clear, go up a little and try again. Never force it. - Cold during a surface interval. Get dry, put on a windproof layer and have a warm drink. Tell your instructor if you are shivering. - Buoyancy still feels rough. Completely normal on Dives 1 and 2, and it keeps improving with every dive. Our buoyancy guide has tips. - Anxiety on the descent. Hold the descent line, look at your buddy, breathe slowly. Tell your instructor before the dive that this happens, and they will pace the descent for you.

Tips for getting the most from your open water dives

- Own your mask before you turn up. A leaking hire mask can spoil Dive 1, and several schools ask you to bring your own mask, snorkel and boots anyway. See Choosing Your First Mask, Snorkel and Fins. - Brief and debrief actively. Ask questions during the briefing if anything is unclear. After each dive, go over what went well and what didn't with your instructor while it's fresh. - Slow your finning. Long, relaxed kicks use less air. You are not racing. - Check your air often. Until checking your gauge becomes a habit, set yourself a routine. - Log every dive. Fill in depth, time, conditions and marine life straight after the dive; several schools include a logbook or a digital one. - Eat between dives. A snack and water on the surface interval prevent the energy crash that makes the second dive of the day feel harder. - Stay engaged with your instructor. Calm students who ask good questions make it easy for the instructor to give them more time on the skills they're finding hard.

What happens immediately after Dive 4

Once your instructor signs off your training, your certification is processed by the agency (PADI, SSI, NAUI or whichever your school uses). Most courses now issue a digital card; a plastic card is often an optional extra (Perth Diving Academy charges $25).

As a PADI Open Water Diver you can:

- Dive to 18 metres with a buddy, without an instructor. - Hire gear and get tanks filled at dive shops by showing your card. - Continue your education with Advanced Open Water, Rescue Diver and beyond.

Don't fly too soon: Queensland's dive code advises 24 hours or more after several dives a day or on consecutive days, which describes most courses.

First dives after certification: Dive again soon, at an easy site you know, ideally with a guide or an experienced buddy. Our first 10 dives after certification guide suggests what to practise.

Next steps

- Read What to Expect in the Theory Module so the academic side of your course feels less mysterious. - Revisit Confined Water Dives: What to Expect for the skill drills that lead into Dives 1 and 2. - Browse the SDU dive-site directory to see where Australian schools take students for the four open water dives, and what each site is like.

Sources

- PADI: Instructor Manual, 2021 edition - PADI: Open Water Diver course - PADI Blog: How to ascend and descend safely in scuba diving - SSI: Open Water Diver (ISO 24801-2) training standard - SSI: Pressure and air consumption (training standards and procedures) - NAUI: Standards and Policies Manual, 2026 edition - DAN: Emergency ascents, managing the risks - DAN: Factors contributing to decompression stress - DAN: Motion sickness - PADI Pros' Blog: Standard Safe Diving Practices - US Navy Diving Manual, Revision 7 (public domain) - Queensland Legislation: Safety in Recreational Water Activities Regulation 2024 - WorkSafe Queensland: Recreational Diving, Recreational Technical Diving and Snorkelling Code of Practice 2024 (worksafe.qld.gov.au, PDF) - Abyss Scuba Diving: PADI Open Water Course - Abyss Scuba Diving: Sydney diving conditions and water temperatures - Pro Dive: Learn to Dive Sydney - Pro Dive: Learn to Dive Manly - Pro Dive: Shelly Beach dive site - Dive Centre Bondi: PADI Open Water Course - Frog Dive: PADI Open Water Diver course - NSW Environment and Heritage: Bare Island Bridge closes for essential restoration - Divers Den: Where We Go - Pro Dive Cairns: 5 Day Learn to Dive Open Water Course - Quicksilver Dive: 4 Day Learn to Dive - Scuba Culture: Learn to Dive - Parks Victoria: Notice to Mariners 386(T) 2026, Portsea Pier closed for maintenance works - Diveline Scuba Centre: PADI Open Water Diver Course - Queensland Scuba Diving Company: PADI Open Water Course - Adreno: SSI Open Water Diver Course, Adreno Brisbane - Kirra Dive: Open Water Scuba Course - Adventure Moreton Island: PADI Open Water Course booking page, adventuremoretonisland.rezdy.com (blocks simple scripts; read 14 October 2026) - Perth Scuba: Is Perth Good for Beginner Scuba Divers? - Perth Diving Academy: Open Water 20 (Level 1) - Parks and Wildlife Service WA: Marmion Marine Park - Diving Adelaide: PADI Open Water Diver Course - Adelaide Scuba: Open Water Diver course page, adelaidescuba.com.au (blocks plain scripts; read 14 October 2026) - Marine Safety SA: Notice to Mariners No 41 of 2025 (Temporary), marinesafety.sa.gov.au (blocks plain scripts; read 14 October 2026) - Yorke Peninsula Council: Ardrossan and Edithburgh jetty works update

Header photo: A scuba instructor teaches two students how to ascend safely during an open water training dive at Phillips Dive Park, Guantanamo Bay, by Spc. Megan Leuck, Joint Task Force Guantanamo, public domain, via Wikimedia Commons.