why electrical cables aren't installed in pipes?

[PaulRainbow]

I think quite a few people are confusing standards and regulations. Not you, I hasten to add.

I think you're correct.

Those ISOs are standards. Various bodies will make complying with those standards a regulation.

As i said before, there are no such regulations covering a leisure boat owner from tinkering with his electrickery. In fact, there are no regulations that cover anyone working on private boats professionally. That said, (i've said it before) the ISO is pretty much all common sense and good practice, so anyone working in the industry should be following it as closely as possible.