Just conceptually translate everything to force of gravity. The force of gravity (pounds) trying to push an object beneath the water is resisted by the force of gravity trying to push the water being displaced back to whence it came. If the forces are equal, then the thing floats. So, it’s a perfect correlation. Whatever the boat weighs in air, i.e., pounds of force; it will be the same pounds of force in the water. The variable is the pounds of force acting on the amount of water that it displaces. If it floats, they match., etc.
Of course, pounds of force is related to the mass of the object. A liter of seawater has more mass than a liter of freshwater. So, a vessel has to displace less seawater to say afloat than freshwater; less cold water than warm water, etc. But, the total balance of forces remains the same.
I remember questions in the written exam for a captain’s license about maximum load “restrictions”, or related, on vessels entering fresh waters.
Of course, pounds of force is related to the mass of the object. A liter of seawater has more mass than a liter of freshwater. So, a vessel has to displace less seawater to say afloat than freshwater; less cold water than warm water, etc. But, the total balance of forces remains the same.
I remember questions in the written exam for a captain’s license about maximum load “restrictions”, or related, on vessels entering fresh waters.
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