Clear and simple yacht partnership agreements ?

[dwp2020]

Hi from Australia.
My son has bought a used but good condition 35ft monohull and has two friends who have agreed to be partners in the cost. But they are interstate and so will not be local to the yacht

These things can work out well, or badly, and it's always hard to tell at the start!

I imagine there are examples of how to document such partnerships out there but I have not been able to find them.

I want to locate something that is easily readable, and ocean and independent lifestyles compatible, and does not need a law degree to understand.
To cover all the common problems that arise, establishes both the entry into ownership and the exits when they come, as well as defining the responsibilities of each partner as well as their rights.
Whatever documents are available, they will of course have to be massaged to meet the specific needs of their circumstances and that may need legal advice.

Keen to hear any thoughts, and look over any documents, on how to proceed here that I can pass on to my son.

Thanks in advance to all who are able to respond!
David