Being a "helpful diver" with other divers is really more about doing the things a good dive buddy would do and being courteous towards others. If I bring a couple pieces of candy, I'm bringing enough for others if they want it. Getting water for seated divers or handing them a snack if you are the one standing seems like the courteous thing to do. Not sure it gets you bonus points with the captain though.
I like to dive with people like you, friendly gestures go a long way.
