Don't quite understand your question.
Are you asking "Is a certified dive master required on a dive boat, hired for charter, in order to make a dive?"
or: "Can a friend who owns a boat provide me a means of conveyance to a site which I choose to dive without having to have a certified "dive master" on board?"
One musn't miscontrue the difference between the differences in the term "dive master".
In the educational/certifying agency definition, a "dive master" is a diver who has been trained to a certain level within that organizations accreditation structure to be able to instruct or assist in instruction.
To address the first part of your question . . . on a dive boat, gosh, the guy may not even be a certified open water diver. He is just the guy that goes down, ties onto the buoy, or wreck, or whatever and guides the dive.
And on many of the dive boats from which I've dived, I think the definition is the latter.
Can't answer the first, but the answer to the second is "yes".
All your friend is doing is providing you a means of conveyance from a position on shore to a position off shore. Now I'm addressing only those issues concerned with diving. His only responsibility is provide a safe means of transport that would be deemed usual and customary with resonable prudence, and all that other legal garbledeygook. His only liability is getting you from shore to your destination and back to shore without incurrence of damages, personal injury or loss. (I'm not a lawyer, although I told a young lady I was a long, long time ago to see if it would help me get "lucky") so, by no means is this legal counsel.
the K