Copying a board ...ethics

Hi there

Ive got an ethical question.

I went in to surfboard shop and asked if I could take some measurements off a board cause I said I was making a board for myself.

My intention was to make a board very close to the one and practice my skills on a board I would like to ride etc.

He said to me no worries! then later on he changed and said they might get into trouble having people off the street taking measurments off the “big names” designs.He also said ‘someone has worked hard at getting this design down and your just ripping him off!’

At what point does it become ethically wrong when you reference or copy someones design?

Sorry guys youve anwsered it in the Archives !