Glass Bottom & Semi-Submersible Boat Tours Explained: See The Reef Without Getting Wet!

What's the difference between a Glass Bottom Boat and Semi-Submersible Boat Tour?

Both experiences let you see the Great Barrier Reef without getting wet, but they’re designed quite differently and offer slightly different viewing experiences.

Let us break the differences down for you and how you can join one of these boat tours.

GLASS BOTTOM BOAT TOURS (GLASSY)

The Glass Bottom Boat Tour at Green Island with Big Cat

Glass bottom boat tours let you peer directly into the underwater world of the Great Barrier Reef — no snorkel or wetsuit needed! These boats have specially designed transparent viewing panels in their hulls that give you a front-row seat to colourful corals, schools of fish, rays and even turtles.

How it works: The Glass Bottom Boats remain at a reef location or an island. It can be included in your package for your reef trip or at an additional cost. Passengers sit on seats above the glass panels and look straight down into the water.

What the experience feels like:

• You’re sitting above the water

• The boat has a skipper operating the motor with times of drifting over the coral with no motor for better viewing

• Smaller, more intimate groups

• Often guided with live commentary from the skipper

  
  

Best for:

• Families with young children

• Elderly guests

• Visitors to the islands on half day tours

• Guests wanting a quick reef preview before snorkelling

• Non-swimmers

  
  

What you’ll see:

Coral gardens, reef fish, giant clams, sometimes turtles — depending on conditions and location.

🛥️ Where You Can Join a Glass Bottom Tour

• Green Island – Explore the reef gardens just offshore on a modern glass bottom boat, complete with commentary from the crew.

• Fitzroy Island – Join a scheduled glass bottom tour while visiting this rainforest-fringed island paradise.

• Outer Reef Activity Pontoons - Operators like Sunlover & Reef Magic include a Glass Bottom Boat Tour as part of their full-day reef experience.

• Reef Cruises - Operators like Ocean Freedom, Wavedancer Port Douglas & Seastar include a Glass Bottom Boat tour in their package.

👉 These tours usually run for around 30–40 minutes 

SEMI-SUBMERSIBLE BOAT TOUR (SEMI-SUB)

The Semi-Submersible Tour with Quicksilver

Semi-submersible boat tours take reef viewing a step further. These specially designed vessels sit low in the water with large underwater windows, giving you expansive views of reefs and marine life from inside a dry cabin — like being in an underwater aquarium!

How it works: The Semi-Sub boats remain at a reef location or an island. You walk down into the vessel and sit inside an air-conditioned underwater viewing chamber looking out at coral walls and shelves. The Skipper is located above deck and usually, a second crew member delivers real-time commentary from within the cabin.

What the experience feels like:

• You’re seated partially below sea level

• Looking out through large panoramic windows

• Feels more like being inside an aquarium

• Slower cruising through the centre of reef structures

• Gain a scuba divers point of view without getting wet

  
  

Best for:

• Non-swimmers

• Elderly guests

• Those unable to Scuba Dive

• Visitors to Green Island for a half day with Big Cat

• Anyone wanting a more immersive dry experience

  
  

What you’ll see:

Reef walls, coral bommies, schooling fish, sometimes reef sharks and turtles — especially on Outer Reef Pontoons.

🚢Where to Find Semi-Submersible Tours

• Sunlover Pontoon – Spend the day on the pontoon and hop onto a Semi-Sub as part of the reef activities.

• Reef Magic Pontoon – This pontoon experience includes semi-sub tours, along with snorkelling and glass bottom boats.

• Great Adventures – This Semi-Sub is the largest on the Great Barrier Reef.

• Down Under Cruise & Dive - An optional Semi-Sub tour is available on the day at an additional cost.

• Frankland Islands - This Semi-Sub tour will take you to reef systems not accessible by snorkelling.

• Ocean Spirit Michaelmas Cay - A comfortable Semi-Sub cruise to the deeper sections of the reef at Michaelmas Cay.

• Quicksilver Agincourt Reef - Departure for this day trip to the reef departs from Port Douglas with a Semi-Sub boat cruise included in your package.

👉 These tours usually run for around 30–40 minutes