Coastal boats are made for saltwater. Their body, their rigging systems all fit salty water. The boat will definitely withstand corrosion resulting from salty water and salty winds. Plus: Good to know: Your boat goes slightly faster than in fresh water. There is a correlation from boat speed and salt water
Really: Boat speed depends on the salt content of your water. Your speed at your fresh water lake might be different from the northern sea or even at the Dead Sea, east of Jerusalem. The salt content of the water will make the difference. The salt content will influence the density of the water.
Density is defined as mass per unit volume. If two objects are the same size, say a defined paper plate and a same size ceramic plate, we say that the ceramic plate is denser than the paper plate. The ceramic plate has the same volume, but much more mass.
What does it mean for your boat:
Boat speed and salt water: Opposite idea?
Off course there are always different opinions. There are some voices saying, boats go faster in fresh water because it is less dense. Less density means less friction while water displacement. Some boat users in blogging forums state, boats will go about 1-2% slower in saltwater because there is more resistance caused by salt particles. We cannot verify this theory. Maybe we will find an expert soon.
Purchasing a lighter, carbon boat?
Another speed relating factor: 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.