Нос судна медленно поднимается.

Yes, нос literally means nose, but Russian often uses it metaphorically for the front part of something. With ships and boats, нос means the bow.

So:

• нос человека = a person’s nose
• нос судна = the bow of a vessel

This is very natural in Russian.

Because судна is the genitive singular form of судно.

Here, Russian is expressing the bow of the vessel, so the second noun goes into the genitive:

• судно = vessel, ship
• нос судна = the vessel’s bow / the bow of the vessel

This is a very common Russian pattern:

• дверь дома = the door of the house
• крыша машины = the roof of the car
• нос судна = the bow of the vessel

Нос is in the nominative singular because it is the subject of the sentence.

The verb поднимается is singular, so it agrees with нос:

• нос ... поднимается = the bow ... rises

Even though English might focus on the whole phrase the bow of the vessel, grammatically the core subject in Russian is нос.

Here поднимается means is rising, goes up, or lifts upward.

It comes from подниматься, which is the imperfective verb meaning to rise / to go up / to lift oneself / to be raised depending on context.

In this sentence, it is describing the bow moving upward on its own, so the most natural translation is:

• is rising
• is lifting
• goes up slowly

The -ся ending often marks a verb as reflexive, but in practice it does more than just mean oneself. It can also make a verb intransitive or give it a middle/passive-like meaning.

Compare:

• поднимать = to raise something
• подниматься = to rise / to go up / to be raised

So:

• Волна поднимает судно. = The wave raises the vessel.
• Судно поднимается. = The vessel rises / is rising.

In your sentence, поднимается shows that the bow itself is moving upward, rather than actively raising something else.

Because the sentence describes an ongoing process: the bow is slowly rising.

The imperfective verb подниматься is used for:

• processes in progress
• repeated actions
• general descriptions

That fits well with медленно and the present-time scene.

A perfective present form normally expresses future meaning in Russian, so it would not fit the same way here.

Медленно is an adverb meaning slowly.

It modifies the verb поднимается and tells you how the action happens:

• поднимается медленно
• медленно поднимается

Both mean rises slowly.

No, Russian word order is fairly flexible. The neutral order here is:

• Нос судна медленно поднимается.

But other orders are possible, for example:

• Нос судна поднимается медленно.
• Медленно поднимается нос судна.

The basic meaning stays the same, but the emphasis changes:

• starting with Нос судна makes the bow the main topic
• starting with Медленно emphasizes the slow movement

So the given order is natural and neutral.

Russian has no articles, so there is no direct equivalent of the or a/an.

Whether something is understood as the bow, a bow, the vessel, or a vessel depends on context.

So:

• Нос судна can mean the bow of the vessel, the bow of a vessel, or something similar depending on the situation.

In practice, context tells the listener which one is meant.

Sometimes yes, but the meanings are not identical.

• судно = vessel, craft; a broader and often more technical term
• корабль = ship; often more specific and less technical

So:

• нос судна sounds a bit more formal, technical, or maritime
• нос корабля is also natural, but slightly different in tone

If the original sentence is from a nautical or technical context, судна makes very good sense.

The stress is:

• нос сýдна мéдленно поднимáется

A rough pronunciation guide for an English speaker:

• нос = nos
• сýдна = SOOD-na
• мéдленно = MYED-lin-na
• поднимáется = pad-nee-MA-ye-tsa

A few useful notes:

• о in unstressed position is reduced, so it may sound closer to a
• я in -мается gives a ya sound
• -ся at the end is often pronounced more like -tsa

Grammatically, it can do either, because the Russian present tense often covers both:

• happening now
• general/habitual action

But in this sentence, because of медленно and the concrete image, the most natural reading is that it is happening right now:

• The bow of the vessel is slowly rising.

Without more context, that is the best interpretation.

Because the subject is singular: нос.

Even though нос судна contains two nouns, the true subject is just нос. The phrase судна only tells you whose bow it is.

So the verb must be singular:

• нос ... поднимается

If the subject were plural, the verb would also be plural:

• носы судов медленно поднимаются = the bows of the vessels are slowly rising