Theory:

     The boat was too far for me to see what was happening. I tugged at the Captain’s sleeve. “What are they doing, Sir? Have they rescued the man?” I asked him.
 
     “They’ve caught him by the arms and are pulling him towards the boat.” He was giving me a running commentary. “Oh what bad luck! A sudden current has swept the man away dragging two of the sailors with him.” He sounded nervous. Just then he noticed the passengers crowding against the railings. “Keep away from those railings!” he shouted. “We don’t want another accident.” The ship had dropped anchor but was heaving up and down.
Explanation:

The crew managed to reach him. Nothing terrible had happened to him till that time. Nature had pitied that sick patient and helped him be alive, even during the adverse situation.
 
The victim's hopeless moments.jpg
The victim's hopeless moments
 
The crew started to pull him by catching his arms. The captain was giving running commentary on the rescue operation to Vasantha as she was more tensed about the man's situation.
 
Unfortunately, there was yet another rising tide. A strong wind carried the man away, dragging two of the sailors behind him. While looking through his binoculars, the captain became restless. His sadness was noticeable in his voice. Moreover, he observed people surrounding the deck, leaning against the railings.
 
deck.jpg
The ship's deck
 
He was shocked to notice people against railings because he didn't want to see another accident. He warned people on the deck to stay away from the railings. The ship was not in a standard position due to the rough sea weather, even though the captain had dropped the anchor in the sea.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Heave
To move up and down or in and out
2.
Tide
A regular rise and fall in the level of sea
3.
Nervous
Anxious or afraid of something
4.
UnfortunatelyUnluckily
Reference:
State Council of Educational Research and Training (2018). Term-3 English Standard-7. Man Overboard - Vasantha Murthi (pp. 125-130). Published by the Tamil Nadu Textbook and Educational Services Corporation.