Question on waterline

[frenchinamst]

I found a simple solution to draw a perfect straight waterline, but before to do it, i want to be sure that its always a "simple line" who show where is the waterline...

Or does it get another function ?

[reigels]

If you�re asking about the true waterline, how the boat sits in the water, it will be a straight line (in calm seas), although the position will change depending on loading and trim of the vessel.

If the question is about the painting of boot topping, or anti fouling paint, that would depend on the ship you are modeling, either being straight or in some cases following the shear of the hull for aesthetics.

[wefalck]

Painted waterlines (boot tops) not necessarily follow the (main) rail/deck sheer. However, to counteract the visual-psychological effect that a straight line (the waterline) tends to look slightly bent downward when placed beneath another line (the line of e.g. the rail), it is given a slight bent upwards towards both ends. This practice is century old. In the old days this was even more important as wooden ship tended to 'hog' with time, i.e. the ends tended to sag downwards because on everage they were less buoyant in heavy seas than the midship section.

In vernacular craft, fishing boats and the like one often sees a wedge been painted at the bow, mostly in white, and tradition has it that this gives the boat an appearance of speed.

As alluded to above the trim of a ship is another matter. Depending on the amount and distribution of cargo, the painted waterline may be well above or below the actual waterline and not necessarily parallel with it. This is not so pronounced in warships, as their load line and trim doesn't vary that much from the design one.

It may be also noted that at least on merchant ships painting the water line (usually without boot top) is often done by eye rather than be accurate measurement. So the real thing may not have the nice clean line we are accustomed to see on models. This creates a bit of a dilemma for the modeller, as reproducing the original too faithfully may be rather perceived as shoddy workmanship.

wefalck