Do Boats Go Faster In Saltwater Or Freshwater? (Explained)

Regardless of your disposition and love of sailing, speed is exhilarating and can turn an adventure into a high-speed thrill.

You may have the fastest boat on the market, but you’re probably wondering what will make it go even faster.

Here’s an Idea of Boat Speed in Saltwater and Freshwater Conditions:

With all other factors being equal (boat type, water temperature, weather, weight), boats will travel 1-2% faster in saltwater environments. The higher density of saltwater will allow your boat to float higher on the water’s surface. Less hull in the water means less drag, hence faster speed.

Here are the more technical details of what’s going on below the surface, literally speaking:

Saltwater And Freshwater Have Different Densities

Buoyancy all comes down to density.

The more displacement or weight of a boat, the deeper it will rest in the water.

A boat displaces the weight of water equal to its own weight. With more hull in the water, resistance is increased. That’s why lighter boats or reducing the weight of a boat always enables it to go faster.

Saltwater has a higher density than freshwater, so your boat will not sink as far into the water. Since salt ions are heavier than water molecules, the dissolved salts increase the mass by a large proportion of the volume, making it denser than fresh or pure water.

Basically, the higher your boat floats, the less hull in the water, the less drag on the hull moving through the water.

The increase in speed in saltwater is only 1 or 2%, though, so don’t expect a huge change.

Check out this article we wrote about 20 Boat Types people ask about when it comes to Saltwater!

What Else Affects The Speed Of A Boat?

The effect of different elements on a boat, in both fresh and saltwater environments, comes down to a few different factors – the type of craft, weather conditions, weight of the craft, and water temperature:

1) Water Temperature

Colder water has a higher density than warmer water and will allow watercraft to float higher on the waterline.

Warmer water is less dense, and therefore your boat will tend to sink a little lower. This can slow down the boat.

The higher a boat is on the waterline, the faster they are going to travel. Variations in salinity also cause the freezing point of seawater to be somewhat lower than that of freshwater.

If saltwater is colder, it can have a higher density than cold freshwater.

There is another bonus to cold water and speed. The air over cold water is denser than air over warm water. Denser air produces more force on sails and better combustion in engines.

Too bad that the warmer the water, the better for those looking for a great boating experience. Again this difference is quite small.

2) The Type of Craft

Obviously, the kind of boat you are sailing is going to have an impact on speed.

A small fishing boat will never catch up to the speed of a racing speed boat, but neither is it supposed to.

Not to mention the type of engine or perhaps even paddle that you have will affect speed. A high horsepower engine on a smooth, swift boat will propel you further and faster than something bulky like a pontoon boat.

A sharp, well-designed canoe will slice through a river current better than any inflatable raft.

Each type of watercraft is meant to be used for its intended purpose and will have its own speed, with a few exceptions.

3) Weather Conditions

High winds may be great for a sailboat, but those tall waves can easily slow down any craft.

The stormier the weather, the more your boat can be bogged down by dangerous conditions.

Depending on the type of boat, too, the differences in weather conditions may slow down your ship. Freshwater during a storm, too, can be much less intense than a huge ocean swell. Large ocean undulations, usually affected by major storms, are called swells.

These swells cause ripples that can eventually create massive waves. The unpredictable currents of swells and large oceanic waves will have a much bigger impact on a ship than freshwater crafts.

On the other hand, sunny days with water that looks like smooth glass can get those boats up to very high speeds with less resistance.

4) Weight

The lighter the boat, the faster the speed.

Heavy cargo or many people on a boat will affect weight distribution and will most likely result in a much greater resistance to speed.

While this may seem pretty self-explanatory, there is also a question of the materials that your boat is made out of. If your boat is made from heavier materials, such as iron on a freighter, it won’t matter how little cargo you fill the boat with.

In fact, there may not be anything you can do at all, depending on the materials of your craft.

If you’re looking to increase your boat’s speed, make sure to travel lightly and perhaps with only a few close friends.

Also, think about getting a boat made of lighter materials.

Can I sail a Saltwater boat in Freshwater (And Vice Versa)?

Because technology has come so far, you can sail nearly every kind of boat no matter the type of water you are sailing in.

While some boats are better for different bodies of water (i.e., canoes in rivers and speedboats in large lakes), you can sail nearly everywhere these days.

Many people believe that the type of craft they choose takes a toll on their speed, especially when mixing a freshwater boat with a saltwater environment. That’s not the case.

While there is a slight difference in performance between freshwater and saltwater, the difference is similar for all boat designs.

The big difference between boating in freshwater and saltwater is the corrosive effect of saltwater. Be sure you are protecting the metal parts of your boat and engine from salt corrosion.

Follow the manufacturer’s recommendations to be sure your boat will operate reliably.