С пирса было видно, как рядом с маяком медленно плывёт лодка.

Because с + genitive here means from.

• с пирса = from the pier / off the pier
• на пирсе = on the pier

So С пирса было видно... means From the pier, it was possible to see... or You could see ... from the pier.

A learner often notices that English uses from, while Russian uses с. That is completely normal here.

Было видно is a very common impersonal Russian expression meaning:

• it was visible
• you could see
• one could see

Here:

• видно = visible / can be seen
• было puts that idea into the past

So the whole opening means something like It was visible from the pier... or more naturally in English, From the pier, you could see...

This is an impersonal construction, so Russian does not need a normal subject like я or мы.

Because лодка is not the subject of было.

The structure is:

• С пирса было видно = main clause
• как рядом с маяком медленно плывёт лодка = subordinate clause

In the main clause, there is no real grammatical subject. That is why Russian uses the default impersonal form было.

The feminine noun лодка belongs only to the second clause, where it is the subject of плывёт.

Literally, как often means how, but in this sentence it introduces what was seen.

So:

• было видно, как... = you could see ...
• more literally: it was visible how...

In natural English, you usually would not translate как as how here.
Instead, you would just say something like:

• From the pier, you could see a boat slowly moving near the lighthouse.

Russian often uses как after verbs or expressions of perception when talking about an action being observed.

Usually как is better here.

Why? Because как emphasizes the action unfolding before your eyes. The speaker is not just stating a fact; they are describing something visually observed.

• видно, как плывёт лодка = you can see the boat moving
• видно, что лодка плывёт = it is evident/apparent that the boat is moving

So:

• как = the action is directly seen
• что = more like a fact or conclusion

In this sentence, как is the natural choice.

Рядом с requires the instrumental case.

So:

• маяк = lighthouse
• с маяком = with / beside the lighthouse
• рядом с маяком = next to the lighthouse / near the lighthouse

The form маяком is the instrumental singular of маяк.

This is a good phrase to remember as a chunk:

• рядом с + instrumental

Examples:

• рядом с домом = next to the house
• рядом с рекой = next to the river
• рядом с маяком = next to the lighthouse

Because Russian prepositions often change meaning depending on the construction and the case.

Here you have two different patterns:

1. с + genitive
   с пирса = from the pier

2. с + instrumental after рядом
   рядом с маяком = next to the lighthouse

So even though both use с, they are different grammatical combinations.

This is very common in Russian, and the case helps tell you which meaning is intended.

This is the classic Russian motion-verb distinction.

• плывёт = is moving in one direction right now
• плавает = swims/sails around habitually, repeatedly, or without one clear direction

In this sentence, the speaker is watching one specific boat moving slowly in the scene. So плывёт is the right choice.

Compare:

• Лодка медленно плывёт к берегу. = The boat is moving toward the shore now.
• Эта лодка часто плавает здесь летом. = This boat often sails here in summer.

Russian word order is flexible, and the end position often gives a word special informational weight.

Here, the sentence first sets the scene:

• from the pier
• near the lighthouse
• slowly moving

and only then names the thing being watched:

• лодка

This can make the sentence feel more visual or cinematic.

A more neutral order is also possible:

• С пирса было видно, как лодка медленно плывёт рядом с маяком.

Both are grammatical, but the original version sounds more descriptive.

Because лодка is the subject of плывёт.

In the subordinate clause:

• лодка плывёт = the boat is moving

Since the boat is doing the action, it stays in the nominative case.

If it were a direct object, then you might expect the accusative, but that is not the structure here.

Медленно is an adverb, and it modifies the verb плывёт.

So it tells you how the boat is moving:

• плывёт = is moving / sailing
• медленно плывёт = is moving slowly

Russian adverbs are often quite mobile in the sentence, so you could also hear:

• лодка медленно плывёт
• лодка плывёт медленно

The meaning stays basically the same, though the emphasis may shift slightly.

This can feel strange to English speakers, but it is possible in Russian.

• было видно sets the viewpoint in the past
• плывёт presents the visible scene as if it is unfolding before the observer’s eyes

This can make the description feel more immediate and vivid.

So the sentence is roughly like:

• From the pier, you could see a boat slowly moving near the lighthouse.

Russian could also use the past in the second clause:

• С пирса было видно, как рядом с маяком медленно плыла лодка.

That version is also correct.
The present плывёт can sound a bit more scenic or vivid.

Strictly speaking, yes: плывёт has ё, and the stress falls there.

In ordinary printed Russian, ё is often written as е, so you may see:

• плывет

But it is still pronounced плывёт.

That is useful for learners because ё always carries stress.

So the important pronunciation here is:

• плывёт
• маякóм
• пи́рса