I bought a while ago a shortboard (Lost Speed Daemon 2) second hand which had the following dimensions. 6'4" - X 3/4 - 2 7/16. I want to find out the volume it has.
I still don't know what is the volumen 31L or 33L (according to https://nulltuul.com/surfboard-volume-calculator/) as the X might be 18 or 19 .
Not a big drama anyway but want to take it as a reference for my next board.
Picture of the board dimensions:

Do you know guys which one is it 18 or 19?
Thanks for the help.
Jo