What is the Difference Between Freshwater and Saltwater ?

Most people other than divers think there is a no difference between salt and fresh water.
As a diver you need to understand the difference and account for it when you change from one type water to the other. There are certain environments that tell you if a body of water is salt or fresh. Before you go on a dive, or trip, you need to find out and ask what the water is. You need to put this information into account as you make your planning. (Click on Picture to link to Phuket, Thailand diving - Great place to dive.)

FRESHWATER

Freshwater sites are lakes, quarries, springs, and rivers. Many of these require special training before you participate in them. Many also may be in the higher altitudes, again, you need special training to dive in higher altitudes.

Remember that in freshwater you need to consider currents, bottom compositions, limited visibility, thermoclines, cold water and entanglements.


SALTWATER

Saltwater sites include for the most part oceans. These fit into 3 general classifications according to temperatures: temperate, tropical, and polar. The vast majority fits into temperate and tropical.

General considerations for these environments include waves, surf, currents, coral, boats, deep water, marine life and remote locations.

Enough about definitions and types, how does it effect me as a diver ? It has to do with buoyancy. First off fressh water weight less per cu foot than salt water. Just for referenec: freshwater weighs 62.4 pounds / cu foot, and saltwater weighs 64.0 pounds / cu foot. Ok , so.

Since freshwater weighs less than saltwater, you're not as buoyant for a given displacement. This means that if you dive in freshwater after you dive in saltwater, assuming you dive in the same gear and exposure suit, you'll need less weight.

So lets say in saltwater you dive with suit etc, and 15 pounds of extra weights than you go to do a dive in freshwater, you might be albe to do it with 8 - 10 pounds. Just remember that if you go from fresshwater to saltwater you will need to add on weight, from saltwater to freshwater, you will take some weight off.

The amount of weight to adjust will be based on experience in the water as far as comfort, the amount of salt in the water, and how you are breathing underwater that day. Just keep in mind that there is a difference between the weight you use in freshwater and saltwater are different.