De or het boordinstrument?

The correct Dutch article is:

het boordinstrument

Rule Words ending in -ment: usually het. See the rule

How to use boordinstrument

the boordinstrumenthet boordinstrument
this boordinstrumentdit boordinstrument
that boordinstrumentdat boordinstrument
our boordinstrumentons boordinstrument
your boordinstrumentjouw boordinstrument
every boordinstrumentelk boordinstrument
which boordinstrument?welk boordinstrument?
a big boordinstrument / the big boordinstrumenteen groot boordinstrument, het grote boordinstrument