Learn Dutch: We varen naar het zuiden en gaan naar boven. - We sail to the south and go upstairs.

The word boven on its own indicates a fixed location, meaning you are already upstairs or above. Because the verb gaan shows movement toward a destination, we have to add naar to create the directional form naar boven (upwards or upstairs).

Why does south get an article (het zuiden) but upstairs doesn't (naar boven)?

Compass directions like zuiden function as nouns in Dutch, so they take the definite article het. Words like boven, beneden, binnen, and buiten are spatial adverbs, not nouns, so they never use an article.

Why is there no second we before gaan?

Just like in English, when two actions are performed by the exact same subject and connected by en (and), you can drop the subject the second time. It is a shorter way of saying We varen naar het zuiden en we gaan naar boven.

Does naar boven always specifically mean upstairs?

Not always! It simply means moving to a higher place. On a ship with multiple decks or in a house, it naturally translates to upstairs. In other contexts, like hiking a trail or flying a kite, it just means up or upwards.