Apr 2020

Discover Freshwater Diving

By Becky Evers

With a big focus on the marine environment within scuba diving, freshwater diving often gets overlooked, despite being more accessible to most people living inland and in colder climates. Freshwater can bring a new experience, with contrasting fish species, topography and in many cases, super clear visibility.

Often exclusively shore dives, the static nature of most freshwater sites means that they develop without saltwater ocean currents and migrating aquatic life. These sites provide snapshots of what equates to years and years of evolution; eroded rocks and caverns, mangrove forests and crystal formations make up these fascinating underwater grottos.

Image Credit: Marc Henauer

Freshwater Diving Tips and Tricks

Buoyancy

Freshwater is less dense than saltwater (as it contains no salt!) and therefore weighs less. This means that an object placed in freshwater will experience less upward force and be more buoyant than in saltwater, so you will need less weight than you do when diving in the ocean. You can approximate this by adding 6-8 % of your body weight to your weight belt or pockets for freshwater, as opposed to the 8 – 10% you would usually add in saltwater. A weight check can be performed in the same manner in both bodies of water, you are correctly weighted if you float at eye level when you’ve fully deflated your BCD and are holding a breath of air at the surface.

Visibility

Although freshwater sites often boast crystal clear visibility, the sedentary nature of most lakes means that there is little to no water movement. On hot days, warm water will sit on the top of the lake and the cold water will remain at the bottom where the majority of material and sediment also lies. This is easy to disturb when diving and can cause murky visibility.

Equipment

Alongside standard diving equipment, it’s a good idea to take a dive knife for fishing line and plant life which can cause entanglement. Even if you are diving in daylight, take a torch as visibility can be murky, particularly when lake diving.

Altitude

Many freshwater lakes and other freshwater dive sites are found up in the mountains at altitude, above 300 metres sea level. Bear this in mind and always check the altitude of the site you are diving as when at altitude, atmospheric pressure is lower than at sea level and this affects the decompression limits of your dive. Change your dive computer settings accordingly and don’t dive outside of your certification level.

Image Credit: Lake Eacham, Blue Dive

 

Freshwater Dive Sites around the World

Lake Malawi

Located between Malawi, Mozambique and Tanzania this huge expanse of freshwater is known as the aquatic highway of Malawi. It is a meromictic lake, as it’s distinct layers of water don’t mix. Also known as Lake Niassa, or the ‘Lake of Stars,’ this picturesque spot makes for an ideal tourist destination with its awesome diving, snorkelling and immersive African culture. Its maximum depth is 706 metres which makes it the 6th deepest lake in the world, it boasts pristine gin-clear waters and 100s of species of colourful fish, many of which are endemic to Lake Malawi.

Image Credit: Timbuktu Travel

Casa Cenote, Yucatan, Mexico

Located close to Tulum, this cenote is just across the road from the beach, combining some saltwater creatures with your typical freshwater fish. You may cross paths with the odd loggerhead turtle, or even a freshwater alligator. Cenotes are on most divers bucket list and this one should make an appearance, stretching out into the jungle it’s clear waters and underground tree roots and mangroves make it a beautiful spot to explore. Kayaks and life jackets are available to rent here.
Image Credit: Deep Dive Mexico

Piccaninnie Pools, South Australia

20 miles South-East of Mount Gambier in Southern Australia, this collection of ponds could be easily overlooked from the surface. However, the eastern side is home to a huge underwater trench nicknamed the ‘Chasm.’ which scales down to 35 metres deep. To the west of this is a majestic underwater cavern with luminous white limestone walls referred to as the ‘Cathedral.’ which makes for a stunning dive. Native freshwater fish reside in the bull reeds, and the remoteness of this beautiful location offers awesome walks along the coastal wetlands with freshwater springs and beaches on land.

Image Credit: Grumpy Grey Nomads

Freshwater Fish & Wildlife

Freshwater fish differ from saltwater fish as they lose salt from their bodies whilst swimming because of the lack of salt content in the water. Fish are constantly taking on water via their gills and membrane, this process is called osmosis. It’s a delicate balance for saltwater fish to not become dehydrated by the salt content of the surrounding water, whilst freshwater fish have to ensure they don’t take on too much water and dilute their mineral and salt intake, as this can cause their cells to burst.

Alongside some pretty awesome species of fish, there are 100’s of species of freshwater turtles. Out of the 365 species of turtles currently identified worldwide only 7 of these are saltwater! This makes for some pretty cool underwater sightings in lakes, rivers and freshwater ponds.

Image Credit: Macarthur Advertiser

Are Saltwater Fish more Colorful than Freshwater Fish?

Fish are generally coloured for camouflage, to defend themselves from their predators and to attract potential mates. Reef fish that can camouflage themselves against brightly coloured coral and anemones are therefore likely to be more vibrant and colourful due to the background they are imitating. There are, however, many brightly coloured freshwater fish; their colouration may be more strategic to counter being discovered by birds and other predators whilst still attracting a mate. Many cichlids and other species of freshwater fish have bright underbellies to combat being seen from the surface.

The great thing about Freshwater diving is that it can be more accessible than saltwater, there may be a lake, river or quarry that is within driving distance. Why not do some research on potential freshwater dives near to you and you may find an opportunity to get in the water more often! Be sure to only dive within your certification limitations and contact your local dive centre for advice on conditions and support before diving any new location.

Happy Freshwater diving!

Featured Image Credit: Anhede

Get the latest deals straight to your inbox.

Becky Evers

My first dive was in 2001 at the age of twelve, My Dad is a Divemaster and he joined me on a try dive in Spain where I absolutely fell in love with the underwater world. Later on in my early twenties I was certified in Egypt and my Father and I regularly took diving holidays together. I became obsessed with fish ID and soon realised that I needed to live somewhere I could dive as often as possible.

At 27 I sold my shares in my company based in the UK and moved over to Thailand to the Similan Islands to complete my DIvemaster course. The liveaboard lifestyle lit my soul, I worked in Koh Tao during the West of Thailand’s monsoon season and then returned to my life in the Similan Islands for another season before travelling to Australia, New South Wales. Here I joined the Reef Life Survey team in surveying the local reefs whilst I continued to fun dive out of my back yard, developing my passion for underwater photography. This was my first experience with temperate water and some pretty intense shore dive entry and exits, I’ve loved adapting to different environments and learning the species that come along with them.

The next part of my professional dive journey is completing my instructor course on the Great Barrier Reef, whilst continuing to expand my survey skills through citizen science and conservation projects.

Qualifications:
PADI Divemaster
PADI Free Diver

Dream Dive Locations:
Palau
Raja Ampat, Indonesia
Cenotes, Mexico
Yolanga Wreck, Queensland