Caminamos hacia la popa por estribor.

It can mean either one.

Caminamos is the 1st person plural form of caminar and it is ambiguous between:

• present: we walk
• preterite: we walked

So the exact time depends on context. In a story, it will often mean we walked. In a description of what people usually do, it could mean we walk.

Hacia means toward or in the direction of.

• hacia = toward
• la popa = the stern / the rear of the ship

So hacia la popa means toward the stern.

The article la is used because popa is a normal noun, and in Spanish you usually say la popa, not just popa, in this kind of sentence.

Popa is a nautical term meaning stern, the back/rear part of a ship.

Useful related terms:

• la proa = the bow
• la popa = the stern
• babor = port
• estribor = starboard

So this sentence is using standard ship-direction vocabulary.

Here por estribor means along the starboard side or via the starboard side.

• estribor = starboard
• por here expresses the route, side, or path taken

So the idea is not just the destination, but which side they moved along while going there.

A natural English translation is something like:

• We walked toward the stern along the starboard side.

Because por and a do different jobs.

In this sentence:

• hacia la popa tells you the direction/destination
• por estribor tells you the path/side used

So:

• hacia la popa = toward the stern
• por estribor = along/by way of the starboard side

If you changed the preposition, the meaning would shift. Por is the natural choice when talking about movement through, along, or via a place or side.

Because estribor and babor are often used in fixed nautical expressions without an article, especially after prepositions.

So forms like these are normal:

• a estribor
• por estribor
• a babor
• por babor

This is similar to how some directional or technical expressions become set phrases.

Spanish is being very logical here:

• Caminamos = action
• hacia la popa = where we were heading
• por estribor = which side/path we took

So the sentence first gives the verb, then the destination/direction, then the route.

That order is very natural in Spanish. You could sometimes rearrange parts for emphasis, but this version sounds straightforward and normal.

Not very naturally.

A very literal version would be:

• We walked toward the stern by starboard.

That is understandable, but natural English would usually be something like:

• We walked toward the stern along the starboard side.
• We headed toward the stern on the starboard side.

So the Spanish sentence is simple, but the best English translation usually needs a slightly less literal phrasing.

Yes. Caminar simply means to walk, and it is perfectly normal here.

Even in a nautical setting, Spanish can use ordinary verbs with technical direction words:

• caminamos = we walked
• fuimos = we went
• avanzamos = we moved forward / advanced

So the sentence mixes an everyday verb with maritime vocabulary.

Yes. In English, several translations may fit depending on context:

• along the starboard side
• by the starboard side
• on the starboard side
• via starboard

The core idea is that the movement happened using or following the starboard side of the ship. The best English choice depends on the wider context, but along the starboard side is often the clearest.