Drenched Productions Logo
Night Dive at Sydney Harbour | Expedition Drenched

We Went Night Diving in Sydney Harbour - Rays, Cuttlefish, and Seahorse Hotels

We did a night dive in Sydney Harbour and visited the seahorse hotels. Check out Sydney’s innovative approach to helping local seahorse populations. 

After a bit of a break, we’re getting ourselves and Sylfia ready for a 240km sail over to the big island of Tasmania. But we can’t bring ourselves to leave Sydney without diving into the legendary Sydney Harbour. Most people wouldn’t normally associate a harbour setting with excellent diving, but Sydney breaks all the rules by offering shallow water reefs, deep wrecks, and even sea walls. 

We decided to do something a little bit different and get a glimpse of Sydney Harbour’s underwater residents at night. That’s right – we did a night dive in Sydney Harbour within view of the city. And boy did the abundance of marine life surprise and delight us! We were greeted by stingrays, cuttlefish, jellies, and even cute little seahorses.

The dive site we chose in Sydney Harbour was great because it allowed us to moor Sylfia just a short surface swim away from our entry point, but also because it’s one of the locations in Sydney where you can find ‘seahorse hotels’ – an Australian marine conservation project to help rebuild the dwindling populations of local seahorses. 

Australia’s Seahorse Hotels - Free Rooms

Seahorses have long captured the attention of SCUBA divers and conservationists alike because of their beauty and strangeness. There are 47 different species of seahorse and while not all are currently under threat, a growing number of seahorse species are seeing drastic declines in their populations.

One such seahorse is the White’s seahorse. Named after John White, Surgeon General to the First Fleet, it is one of four species of seahorse that are endemic to the New South Wales area and it is currently listed as an endangered species. They prefer to live in shallow water in or near an estuary environment and have been recorded in eight different estuaries on the New South Wales coast. However, White’s seahorses are found in the biggest numbers in Port Stephens, Port Hacking, and Sydney Harbour. 

To help slow or stop the loss of White’s seahorse populations, the Department of Primary Industries and Sydney’s SeaLife Aquarium joined forces to help create new habitats for these cute little creatures, rebuild their populations through breeding programs, and help educate local Australians about the importance of marine conservation. 

The team at Sea Life Aquarium designed and built 18 custom ‘seahorse hotels’ that they then dropped into the water at Delwood Beach and Little Manly for World Oceans Day in June 2021. These bio-degradable habitats were inspired by lost crab traps and over time they will be overgrown by corals, sponges, and algae that will protect them from predators and a ready supply of vital food for the seahorses. The conservation project hopes to deploy another 100 seahorse hotels in Sydney Harbour and Port Stephens in the coming years. 

We Went Night Diving in Sydney Harbour - Rays, Cuttlefish, and Seahorse Hotels
We Went Night Diving in Sydney Harbour - Rays, Cuttlefish, and Seahorse Hotels

The new habitats are only the first piece of the puzzle, though, since an empty hotel is a bad hotel. In September of 2022, Sea Life Aquarium released 111 juvenile White’s seahorses back into the water around Sydney. These little creatures were bred in the aquarium as part of Sea Life Sydney’s seahorse breeding program.

What Happens in the Ocean at Night?

After the sun goes down, the ocean changes from blue to dark black. While it often looks dark and dangerous from the surface, the underwater world turns into a colourful frenzy at night. Creatures of all kinds and sizes migrate from the deep oceans to the surface waters at night to feed, and in some cases, to breed. This movement of marine life is the largest migration of animals in the natural world – and it happens every single day. 

On a coral reef, the daytime belongs to the herbivores. But at night, the plant-eaters take shelter while the nocturnal carnivores come out to hunt. This change in dynamic changes the entire tone of a coral reef. At night, the small fish hide in cracks and crevices and appear terrified, while larger predators (often with adaptations that make them particularly good nighttime hunters) patrol the reef looking for individuals who are weak or have taken a chance and gone too far from home. 

At the end of the night, the carnivores retreat with some going back down into the depths, and others going out into open water, leaving the herbivores free to abandon their hiding places and begin their own daily search for food.

cuttlefish - Australia Harbour | Expedition Drenched
Octopus - Sydney Harbour | Expedition Drenched

What Training Do I Need to Night Dive?

You don’t technically need special training to go night diving. Anyone who’s Open Water certified or higher can go diving at night. However, taking a night diving specialty course is a great way to introduce yourself to the new kind of diving. 

PADI’s night diving specialty course will teach you how to use your dive torch to communicate underwater, how to navigate around dive sites in the dark, and most importantly, it’ll give you a chance to experience a dive at night while under the supervision of a trained professional. 

If you love to gaze over a dive site in the daytime and meet its local marine residents, then you’ll absolutely adore seeing how everything changes once the sun goes down. Even if you night dive on sites you’ve been to many times, it’ll feel like a brand new site with a whole new cast of underwater creatures. 

 

The Next Chapter of the Expedition Drenched Story

The next part of the Expedition Drenched adventure is going to be a great one. While we’ve been in Sydney we took the opportunity to make some repairs and upgrades to our treasured Sylfia. We stitched up the tears in her sails, replaced all her rope lines, and even had Manu and Tom build some stylish and comfortable outdoor benches out on her bow. She’s never been in better shape or more ready for another adventure on the open seas. 

Our next adventure will have us set sail for Tasmania, the island state located about 240km south of the Australian mainland. And we’ll be sailing there with both some familiar crew faces, but also some new ones. While we’re still sad that Molly and Philip have gone on to bigger and better things, we’re super excited to welcome Mike and Tilly to our band of salty marine conservationists and already love the energy they bring to the crew. 

Follow our channel on YouTube and make the sail to Tasmania with us. You won’t regret it since Tasmania has some of the best temperate diving in the world. From shipwrecks to caves to sea dragons and beyond, Tasmania has an underwater world unlike anything else that we’ve seen before. 

It’s time to start a new chapter in our love story with the ocean!

👉Web: https://expeditiondrenched.org

👉Patreon: https://www.patreon.com/DrenchedDivers

👉Facebook: https://www.facebook.com/ExpeditionDr…

👉Instagram: https://www.instagram.com/expeditiond…

👉Merch: https://expeditiondrenched.org/collections/products

 

Expedition drenched is a U.S. based marine educational non profit 501c3 made possible by our donors and patrons. If you love scuba, sailing, travel, adventure, exploration, conservation, and all things aquatic, we really hope you will continue to follow us on our journey. Our goal in making these videos is to show the world all the amazing, beautiful, and strange inhabitants of the ocean in the hopes that we will all be inspired to protect it.

If you liked our video, keep watching them! Subscribe! Thumbs Up!

Let us know what you think in the comments! Share us with all your favorite mermaids and mermen in your life!

Support us on Patreon: https://www.patreon.com/DrenchedDivers

We Use & Love:

Cameras we use:

  • Aerials: DJI Mavic
  • On Land: Sony A7iii, Sony AX-53, GoPro 7

Underwater:

  • Sony A7iii in Nauticam Housing
  • Sony RX-100 in Nauticam Housing Underwater

Lighting:

You Might Also Like:

[mpfy-multi-map map_ids="230" height="350" label="Select Map" label_bg_color="#13c490" ]