One of the ways in which we can clearly see the moral development and growth of Huck Finn is through his attitude to the murderers on the sinking ship that he and Jim have just entered. When they finally manage to escape and make their get away, Huck reflects that it would be terrible for them to be trapped on a sinking ship, and resolves to do something to help them. Note the following quote and what it reveals about Huck's character:
Now was the first time that I begun to worry about the men--I reckon I hadn't had time to before. I begun to think how dreadful it was, even for murderers, to be in such a fix. I says to myself, there ain't no telling but I might come to be a murderer myself yet, and then how would I like it?
Huck clearly shows a growth in his character, because he doesn't simply think selfishly about himself and his own escape, but he also thinks about the fate of the murderers, who do not realise the plight they are in. He begins to think of others and to try and act to help them, even though he does this without necessarily thinking of the consequences of his actions.