N H Dave, "Plimsoul Line "

The markings are also marked for areas and seasons.

Deepest mark = shallowest draught is "WNA" = Winter North Atlantic. Top Mark ie deepest draft+ "TF" = Tropical Fresh.

Take a trip to your nearest port and look at the bows of any ship. The initials by the marks represent the classification society wot calculated the limits. Thus L R = Lloyds Register.

BTW The original act allowed the owners to set thier own load lines. Result ? "Glug, Glug, Glug !!!"

Your pedantic Adjustor of Claims,

Gareth