Is there a direct relationship between ship dislacement in salt water and the summer load line?

Question

I want to be able to set up an equation which calculates any vessel's fresh water load line when only the max summer draft is known.

For instance, one can calculate the max winter draft value by subtracting 1/48th of the max summer draft value from the summer draft value.

Answer 1

Can't be done. There is no mathematical relationship between the two.  The different drafts are determined by estimating the hull's volume based on classification society's load line criteria.  This is done when the ship is designed.  Figures are placed aboard to be used for the life of the ship.  After ship is built there is little need to recalculate displacement unless ship is modified.

Answer 2

the temperature s of the water summer/winter must be known, and the local specific gravity.  then it's easy.

Answer 3

Your asking for two kinds of questions; one that deals with salt water and the other with fresh, as you may know there are differances in the make up of the 2 solutions.

Answer 4

Some Boy,lost me on the beach.

Answer 5

Complex...you need to know the specific gravity of the two bodies of water...you are switching from Fresh water to Salt water. Salt water is less bouyant. Then you need some of the other factors mentioned by other contributors.

Answer 6

To set the equation, you need the fresh water allowance (FWA) for that vessel. It's based on the water plane area (WPA) at the summer draft.