board

1

Once we were on board of the ship, we smiled.
Once we were on board the ship, we smiled.

We say on board an aeroplane, ship or train, without of.

2

Finally we got on board of the plane.
Finally we got on board the plane.
Finally we boarded the plane.

We can say get on board an aeroplane, ship or train, without of.

We can also use board as a verb: ‘We’ll be boarding the plane in ten minutes.’