I have included the sentences I was most doubtful about.
1) The ship was cheered and they left the harbour. They went below the prow (I think "kirk" is the archaic word for "prow")
2)The mariners were then caught (can you say "struck") in (not by) a violent storm, then by mist and snow and finally were surrounded by ice.
3) The storm is personified as a huge bird, chasing the ship with its large wings. The ship drove fast southwards with its sloping masts (I need a synonym for "sloping" and "dipping") and dipping prow chased by the loud storm.
4)The ice growled like a dog, roared like a lion and howled like a wolf.
Colerdige uses metaphors taken from the animal world to express the sounds made by thr ice.
1. "kirk" usually means "church," and I think that's what it means in this context.
http://rapgenius.com/Samuel-taylor-coleridge-rime-of-the-ancient-mariner-lyrics#note-80646
Use Ctrl + F and type in KIRK -- and then hold your cursor over the word to see it defined. You can also find definitions here: http://en.wikipedia.org/wiki/Kirk
Then look at that whole stanza --
The ship was cheered, the harbour cleared
Merrily did we drop
Below the kirk, below the hill
Below the lighthouse top
To me, the image is that as the ship left the harbor, they seemed to go downhill in relation to where the church (cathedral?) and the top of the lighthouse was.
Now ... all that said ... how will you rephrase the first part of that first line?
2)The mariners were then struck by a violent storm, then by mist and snow and finally were surrounded by ice.
3) The storm is personified as a huge bird, chasing the ship with its large wings. The ship sailed fast southwards with its billowing sails and with its prow going violently up and down, chased by the loud storm.
4)The ice growled like a dog, roared like a lion and howled like a wolf.
Colerdige uses metaphors taken from the animal world to express the sounds made by the ice.
Be sure to read very carefully to catch all the changes I made.
1) The sentence "The ship was cheered and they left the harbour. They went below the prow (I think "kirk" is the archaic word for "prow")" appears to be a bit unclear. If you are unsure about the meaning of "kirk," it does not mean "prow." "Kirk" is actually an archaic word that means "church." I believe the correct term you are referring to in the sentence is "prow," which is the front part of a ship. So, the sentence could be rewritten as: "The ship was cheered, and they left the harbor. They went below the prow."
2) Your doubt regarding the sentence "The mariners were then caught (can you say 'struck') in (not by) a violent storm, then by mist and snow and finally were surrounded by ice" is valid. Instead of using the word "caught," a more suitable word to convey the idea of being suddenly affected by the storm could be "struck." Additionally, it is more accurate to say "caught in" rather than "caught by" a storm. So, the revised sentence would be: "The mariners were then struck in a violent storm, then in mist and snow, and finally, they were surrounded by ice."
3) In the sentence "The storm is personified as a huge bird, chasing the ship with its large wings. The ship drove fast southwards with its sloping masts (I need a synonym for 'sloping' and 'dipping') and dipping prow chased by the loud storm," you are looking for synonyms for "sloping" and "dipping" to avoid repetition. Some possible alternatives for "sloping" could be "angled," "tilting," or "inclined." Similarly, for "dipping," you may consider using words like "plunging," "submerging," or "diving." So, an amended version of the sentence would be: "The storm is personified as a huge bird, chasing the ship with its large wings. The ship drove fast southwards with its angled masts and plunging prow, chased by the loud storm."
4) The doubt you expressed regarding the sentence "The ice growled like a dog, roared like a lion, and howled like a wolf" is related to Coleridge's use of metaphors taken from the animal world to describe the sounds made by the ice. Your interpretation is correct. The writer is using figurative language to compare the sounds of the ice to those made by different animals. Therefore, the sentence is correctly expressing this idea.
I hope this clarification helps! If you have any more questions or doubts, feel free to ask.